Insulin favors acute inflammatory reaction in alloxan-diabetic tilapia during infectious aerocystitis / Insulina favorece a reação inflamatória aguda em tilápia do Nilo aloxano-diabéticas durante aerocistite infecciosa

In vertebrates, the inflammatory reaction is responsible for modulating the initial nonspecific defense until specific immunity is acquired. In this context, numerous studies in mammals have demonstrated the participation of insulin in the inflammatory response, favoring cell proliferation and the migratory capacity of endothelial cells, vascular smooth muscle cells and monocytes, as well as mediating the expression of pro-thrombotic and pro-fibrotic factors. However, little is known about the effect of this peptidic hormone on the inflammatory reaction in teleostean fish. In order to evaluate the participation of insulin in the acute inflammatory response of Nile tilapia, Oreochromis niloticus, during aerocystitis induced by Aeromonas hydrophila, and 48 aloxane-diabetic tilapia were used, constituting two groups: diabetics treated with insulin and diabetics without treatment. After six, 24, and 48 hours of inflammatory stimulation, tilapia were submitted to deep anesthesia for euthanasia and necropsy, and thus, obtaining exudate and harvesting of the swim bladder for analysis of the inflammatory reaction. Based on this premise, the present study demonstrated the participation of insulin in the acute inflammatory reaction of alloxan-diabetic tilapia by favors the cellular accumulation in the exudate, the proliferative effect of fibrous tissue and neovascularization in the inflamed site. Such findings reinforce the old hypothesis that insulin plays an important role in the innate immune response during acute inflammatory reaction, being an important pro-inflammatory hormone. However, Nile tilapia proved to be a promising experimental model for studies and advances in research involving diabetes mellitus.(AU)

Em vertebrados, a reação inflamatória é responsável por modular a defesa inicial não-específica, até que imunidade específica seja adquirida. Neste contexto, inúmeros estudos em mamíferos têm demonstrado a participação da insulina sobre a resposta inflamatória, favorecendo a proliferação celular e a capacidade migratória das células endoteliais, células do músculo liso vascular e dos monócitos, além de mediar a expressão de fatores pró-trombótico e pró-fibrótico. Porém, pouco se conhece o efeito deste hormônio peptídico sobre a reação inflamatória em peixes teleósteos. Para avaliar a participação da insulina sobre a resposta inflamatória aguda em tilápias do Nilo, Oreochromis niloticus, na aerocistite induzida por Aeromonas hydrophila, foram utilizadas 48 tilápias aloxano-diabéticas, constituindo dois grupos: dos diabéticos tratados com insulina e diabéticos sem tratamento. Após, seis, 24 e 48 horas do estimulo inflamatório, as tilápias foram submetidas à anestesia profunda para eutanásia e necropsia, e assim, obtenção de exsudato e colheita da bexiga natatória para analise da reação inflamatória. Partindo-se desta premissa, o presente estudo demonstrou a participação da insulina na reação inflamatória aguda infecciosa de tilápias do Nilo aloxano-diabéticas por favorecer o acúmulo positivo celular no exsudato, assim como o efeito proliferativo de tecido fibroso e a neovascularização no local inflamado. Tais achados reforçam a hipótese de que a insulina desempenha importante papel na resposta imune inata na reação inflamatória aguda, sendo um importante hormônio pró-inflamatório. Contudo, a tilápia do Nilo demonstrou ser um modelo experimental promissor para estudos e avanços em pesquisas envolvendo o diabetes mellitus.(AU)

Insulin favors acute inflammatory reaction in alloxan-diabetic tilapia during infectious aerocystitis / Insulina favorece a reação inflamatória aguda em tilápia do Nilo aloxano-diabéticas durante aerocistite infecciosa

In vertebrates, the inflammatory reaction is responsible for modulating the initial nonspecific defense until specific immunity is acquired. In this context, numerous studies in mammals have demonstrated the participation of insulin in the inflammatory response, favoring cell proliferation and the migratory capacity of endothelial cells, vascular smooth muscle cells and monocytes, as well as mediating the expression of pro-thrombotic and pro-fibrotic factors. However, little is known about the effect of this peptidic hormone on the inflammatory reaction in teleostean fish. In order to evaluate the participation of insulin in the acute inflammatory response of Nile tilapia, Oreochromis niloticus, during aerocystitis induced by Aeromonas hydrophila, and 48 aloxane-diabetic tilapia were used, constituting two groups: diabetics treated with insulin and diabetics without treatment. After six, 24, and 48 hours of inflammatory stimulation, tilapia were submitted to deep anesthesia for euthanasia and necropsy, and thus, obtaining exudate and harvesting of the swim bladder for analysis of the inflammatory reaction. Based on this premise, the present study demonstrated the participation of insulin in the acute inflammatory reaction of alloxan-diabetic tilapia by favors the cellular accumulation in the exudate, the proliferative effect of fibrous tissue and neovascularization in the inflamed site. Such findings reinforce the old hypothesis that insulin plays an important role in the innate immune response during acute inflammatory reaction, being an important pro-inflammatory hormone. However, Nile tilapia proved to be a promising experimental model for studies and advances in research involving diabetes mellitus.(AU)

Em vertebrados, a reação inflamatória é responsável por modular a defesa inicial não-específica, até que imunidade específica seja adquirida. Neste contexto, inúmeros estudos em mamíferos têm demonstrado a participação da insulina sobre a resposta inflamatória, favorecendo a proliferação celular e a capacidade migratória das células endoteliais, células do músculo liso vascular e dos monócitos, além de mediar a expressão de fatores pró-trombótico e pró-fibrótico. Porém, pouco se conhece o efeito deste hormônio peptídico sobre a reação inflamatória em peixes teleósteos. Para avaliar a participação da insulina sobre a resposta inflamatória aguda em tilápias do Nilo, Oreochromis niloticus, na aerocistite induzida por Aeromonas hydrophila, foram utilizadas 48 tilápias aloxano-diabéticas, constituindo dois grupos: dos diabéticos tratados com insulina e diabéticos sem tratamento. Após, seis, 24 e 48 horas do estimulo inflamatório, as tilápias foram submetidas à anestesia profunda para eutanásia e necropsia, e assim, obtenção de exsudato e colheita da bexiga natatória para analise da reação inflamatória. Partindo-se desta premissa, o presente estudo demonstrou a participação da insulina na reação inflamatória aguda infecciosa de tilápias do Nilo aloxano-diabéticas por favorecer o acúmulo positivo celular no exsudato, assim como o efeito proliferativo de tecido fibroso e a neovascularização no local inflamado. Tais achados reforçam a hipótese de que a insulina desempenha importante papel na resposta imune inata na reação inflamatória aguda, sendo um importante hormônio pró-inflamatório. Contudo, a tilápia do Nilo demonstrou ser um modelo experimental promissor para estudos e avanços em pesquisas envolvendo o diabetes mellitus.(AU)

Alloxan diabetes alters the tensile strength, morphological and morphometric parameters of abdominal wall healing in rats

To investigate the effects of alloxan diabetes on the abdominal wall healing of rats undergoing laparotomy. METHODS: Ninety-six male Wistar rats weighing between 200 and 300 grams, divided into two groups: non-diabetic group (G1) and another with untreated diabetes (G2). Three months after diabetes induction, the animals underwent a 5cm-long- laparotomy and 5.0 nylon monofilament suture. After the surgery, 12 animals from each group were euthanized on days 4, 14, 21 and 30 corresponding to the moments M1, M2, M3 and M4. In each moment a fragment of the abdominal wall containing the scar was removed for tensile strength measurement, histological and morphometric study. Clinical and biochemical parameters were also analyzed. RESULTS: G2 animals showed parameters compatible with severe diabetes and decreased plasma levels of insulin. The tensile strength in G2 was significantly smaller in M2 and M4, with a tendency to fall in the other two. Through light microscope, diabetic animals showed more difficulty to increase collagen density and contraction. G2 animals showed high cellularity of fibroblasts in later healing moments, with collagen thinning in M2 and M4. CONCLUSION: The abdominal wound healing in untreated diabetic animals was altered and led to a higher incidence of dehiscence and infections.(AU)

Comparison of induction of Diabetes mellitus with alloxan in different doses in Wistar rats / Comparação da indução do Diabetes mellitus com aloxana em diferentes doses em ratas Wistar

Diabetes mellitus is a metabolic disorder associated with hyperglycemia and caused by defect in insulin secretion. The search for better understanding of the mechanisms of induction of experimental diabetes and its complications is very important. The purpose of this study was to compare the induction of diabetes mellitus using alloxan 2% in Wistar rats at different doses. Doses of 120, 150, 200mg/kg alloxan 2% and control group were compared. Hyperglycemia and death were observed in all groups, but the higher glycemia and less percentage of death were significant at a dose of 120mg/kg. Glycosuria, polyuria and polydipsia were present in the animals of the three groups, but were significantly higher for G2 compared to other groups and weight loss was more intense in G1. Decreased urinary density was significant in G2 compared to G1 and G3 and there was an increase in urinary pH in all groups compared to control. Positive results for nitrite occurred in G2 and occult blood in the urine in all groups, with greater intensity for G1 followed by G2 and G3. Alloxan 2% intraperitoneally at the three doses used experimentally induced diabetes mellitus in Wistar rats. The dose of 120mg/kg was the most effective and induced disease in a greater number of animals and cause a lower incidence of death.

Diabetes mellitus é uma desordem metabólica associada com hiperglicemia e causada por defeito na secreção de insulina. A busca por melhor compreensão, dos mecanismos fisiopatológicos de indução experimental do diabetes e suas complicações é de grande importância. O objetivo deste estudo foi comparar a indução do diabetes mellitus, usando a aloxana a 2% em diferentes doses em ratas Wistar. Foram comparadas doses de 120, 150, 200mg/Kg de aloxana a 2% e grupo controle. Hiperglicemia e óbito foram observados nos três grupos, no entanto, a maior glicemia e menor percentual de óbito foram significativas utilizando a dose de 120mg/Kg. Glicosúria, poliúria e polidpsia estiveram presentes nos animais dos três grupos, mas foram significativamente maiores para o G2 comparado aos demais grupos e a perda de peso foi mais intensa no G1. Diminuição de densidade urinária foi significativa no G2 comparado ao G1 e G3 e houve aumento do pH urinário em todos os grupos comparado ao controle. Positividade para nitrito ocorreu no G2 e sangue oculto na urina em todos os grupos, com maior intensidade para o G1 seguido do G3 e G2. Aloxana a 2% nas três doses utilizadas induz experimentalmente o diabetes mellitus em ratas Wistar, sendo a dose de 120mg/kg a mais eficiente por induzir a doença em um maior número de animais e c ausar menor incidência de óbito.

Comparison of induction of Diabetes mellitus with alloxan in different doses in Wistar rats / Comparação da indução do Diabetes mellitus com aloxana em diferentes doses em ratas Wistar

Diabetes mellitus is a metabolic disorder associated with hyperglycemia and caused by defect in insulin secretion. The search for better understanding of the mechanisms of induction of experimental diabetes and its complications is very important. The purpose of this study was to compare the induction of diabetes mellitus using alloxan 2% in Wistar rats at different doses. Doses of 120, 150, 200mg/kg alloxan 2% and control group were compared. Hyperglycemia and death were observed in all groups, but the higher glycemia and less percentage of death were significant at a dose of 120mg/kg. Glycosuria, polyuria and polydipsia were present in the animals of the three groups, but were significantly higher for G2 compared to other groups and weight loss was more intense in G1. Decreased urinary density was significant in G2 compared to G1 and G3 and there was an increase in urinary pH in all groups compared to control. Positive results for nitrite occurred in G2 and occult blood in the urine in all groups, with greater intensity for G1 followed by G2 and G3. Alloxan 2% intraperitoneally at the three doses used experimentally induced diabetes mellitus in Wistar rats. The dose of 120mg/kg was the most effective and induced disease in a greater number of animals and cause a lower incidence of death. (AU)

Diabetes mellitus é uma desordem metabólica associada com hiperglicemia e causada por defeito na secreção de insulina. A busca por melhor compreensão, dos mecanismos fisiopatológicos de indução experimental do diabetes e suas complicações é de grande importância. O objetivo deste estudo foi comparar a indução do diabetes mellitus, usando a aloxana a 2% em diferentes doses em ratas Wistar. Foram comparadas doses de 120, 150, 200mg/Kg de aloxana a 2% e grupo controle. Hiperglicemia e óbito foram observados nos três grupos, no entanto, a maior glicemia e menor percentual de óbito foram significativas utilizando a dose de 120mg/Kg. Glicosúria, poliúria e polidpsia estiveram presentes nos animais dos três grupos, mas foram significativamente maiores para o G2 comparado aos demais grupos e a perda de peso foi mais intensa no G1. Diminuição de densidade urinária foi significativa no G2 comparado ao G1 e G3 e houve aumento do pH urinário em todos os grupos comparado ao controle. Positividade para nitrito ocorreu no G2 e sangue oculto na urina em todos os grupos, com maior intensidade para o G1 seguido do G3 e G2. Aloxana a 2% nas três doses utilizadas induz experimentalmente o diabetes mellitus em ratas Wistar, sendo a dose de 120mg/kg a mais eficiente por induzir a doença em um maior número de animais e c ausar menor incidência de óbito.(AU)

Use of insulin-like growth factor in the healing of open wounds in diabetic and non-diabetic rats

To analyze the effects of application of 1% and 3% insulin-like growth factor I (IGF-1) cream on the process of wound healing in induced skin lesions in diabetic and non-diabetic rats and evaluate its effect on expression of myofibroblasts. METHODS: Ninety-six Wistar adult male rats were divided into six groups, with 16 rats in each group, as follows: group 1: non-diabetic, untreated; group 2: non-diabetic, treated with 1% IGF-1 cream; group 3: non-diabetic, treated with 3% IGF-1 cream; group 4: diabetic, untreated; group 5: diabetic, treated with 1% IGF-1 cream; and group 6: diabetic, treated with 3% IGF-1 cream. In groups 4, 5, and 6, diabetes was induced by intravenous injection of alloxan. After diabetes had been induced, animals were mantained for 3 months. The experimental procedure consisted of the creation of a circular incision of 0.9 mm in diameter using a metal punch. Following this, wounds were treated daily according to the assigned treatment regimen. Groups 2 and 5 were treated with 1% IGF-1 cream, groups 3 and 6 with 3% IGF-1 cream, and groups 1 and 4 and the untreated groups with 0.9% saline solution. From each group, samples from 4 rats were taken at three, seven, 14, and 21 days after the injury. Samples were fixed in 10% formalin to prepare slides for histological analysis. Slides stained with hematoxylin-eosin (H&E) and Masson were observed vascular proliferation, mononuclear cells, polymorphonuclear cells, fibroblast proliferation, re-epithelialization, and collagen fibers. This study analyzed the expression of α-smooth muscle actin using specific antibodies to correlate the temporal expression of α-smooth muscle-specific actin (α-SM actin), a molecular marker for myofibroblast transformation. RESULTS: Macroscopic observation of wounds showed a more rapid re-epithelialization of wounds treated with IGF. Regarding acute inflammatory reactions, the results of the analysis of vascular.(AU)

Diabetes mellitus triggers oxidative stress in the liver of alloxan-treated rats: a mechanism for diabetic chronic liver disease

PURPOSE: To investigate whether Diabetes mellitus chemically induced by alloxan is capable of changing, in the long term, the oxidative balance in the liver tissue of rats. METHODS: Sixty male Wistar rats, weighing 250-280g, were randomly distributed into two experimental groups: NG - 30 non-diabetic control rats; DG - 30 alloxan- induced diabetic rats without any treatment for the disease. Each group was further divided into three subgroups containing ten rats each, which were sacrificed after one, three and six months of follow-up, respectively. Blood glucose, urinary glucose, glycosylated hemoglobin and insulin were determined in the plasma of all animals at the beginning of the experiment and prior to all sacrifice periods. The concentrations of lipid hydroperoxides (HP) and the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were also measured in the liver tissue of all animals. RESULTS: Rats from the DG group showed high levels of blood glucose, urinary glucose, and glycosylated hemoglobin, with significantly lower plasma insulin levels than those observed in NG rats (p<0.001). Diabetic animals also showed increased concentration of HP free radicals in the liver tissue as compared to those shown by NG animals after one, three and six months of follow-up. In contrast, the antioxidant activity of the enzymes SOD, CAT and GSH-Px was significantly reduced in all follow-up periods (p<0.01). CONCLUSIONS: Diabetes determines oxidative stress in the liver, which is characterized by increased concentration of reactive oxygen species (ROS) in tissue and significant reduction in their antioxidant defenses. Such oxidative unbalance in the liver cells may play a relevant role in the genesis of the diabetic chronic liver disease, including the non-alcoholic fatty liver disease and its occasional progression to steatohepatitis and cirrhosis.(AU)

Zinc sulphate administered by transdermal iontophoresis improves breaking strength of surgical wounds in skin of alloxan-induced diabetic rats

PURPOSE:To investigate the effect of zinc sulphate administered by transdermal iontophoresis (TDI) on mechanical resistance of surgical wounds performed in the skin of diabetic rats. METHODS:One hundred and sixty male Wistar rats weighing approximately 250g were submitted to an incision surgery at the anterior region of abdomen and randomly distributed into four experimental groups with 40 non-diabetic control animals (G1) and 40 untreated diabetic animals (G2), both without any treatment of incisions; 40 non-diabetic animals (G3) and 40 untreated diabetic animals (G4), both with incisions treated with zinc sulphate, administered for a period of four consecutive days after surgery, in sessions of ten minutes duration, using a continuous-current electrostimulator (Zn + TDI). Each experimental group was further divided into four subgroups with ten rats each to be evaluated on the 4th, 7th, 14th, and 21st day after surgery. In each period were analyzed clinical and laboratory from the animals, and measured the breaking strength and hydroxyproline content (OH-P) of the skin scars. RESULTS: Breaking strength (BS) was significantly reduced (p<0.05) in skin scars of untreated diabetic rats (G2) on the 7th, 14th, and 21st postoperative days when compared to non-diabetic control rats (G1). In contrast, BS in skin scars of non-diabetic and untreated diabetic rats (G3, G4) treated with Zn + TDI showed significant increase (p<0.05) in those periods when compared with their respective controls with untreated incisions. The OH-P content of the scars did not show statistically significant variation in all studied groups at four different times evaluated after surgery. CONCLUSIONS: Zinc sulphate administered by transdermal iontophoresis had beneficial effect on the mechanical resistance of scars produced in the skin of diabetic rats.(AU)

Long term evaluation of morphometric and ultrastructural changes of testes of alloxan-induced diabetic rats

PURPOSE: To evaluate in a long term the morphometric and ultrastructural changes in seminiferous tubules (ST) of normal and diabetic rats, and to correlate any changes with animal age and diabetes duration. METHODS: Sixty male Wistar rats, three months-old, were randomly divided into two groups: 30 non-diabetic controls (N) and 30 alloxan untreated diabetic (D). After one, six and 12 months of follow-up or diabetes induction rats were sacrificed and the testes examined. Morphometric measures of the ST were performed by digital imaging analysis. ST ultrastructure was analyzed by transmission electron microscopy. RESULTS: Sustained hyperglycemic state was observed in all diabetic rats throughout the study. Serum testosterone was also significantly decreased in these animals. The diameter, total area, epithelium area and epithelium thickness of ST were lower and tubular density was higher in diabetic animals. Diabetic rats also showed ultrastructural changes compromising the whole testis including germ-, Sertoli-, and Leydig cells, and also the mithocondria and cellular nuclei. Most frequent of these consisted of vacuolization and/or accumulation of lipid droplets and electron dense dark material in cell cytoplasm and/or in membranes, cellular degeneration, and apoptosis. Non-diabetic control rats also showed testicular lesions that resemble to the diabetic lesions, although much less severe and with later onset in life of these animals. CONCLUSION: Histopathological changes observed in testes of normal and diabetic rats are closely related to the animal age and/or duration of the hyperglycemic state, being progressively more severe in animals sacrificed belatedly. These changes may play an important role in male infertility observed in diabetic subjects.(AU)

Fisiopatologia da infecção por Aeromonas hydrophila em pacus aloxana-diabéticos

A participação do sistema endócrino no desenvolvimento do processo inflamatório e a sua interação com os hormônios pancreáticos é um sistema complexo independentemente da espécie estudada. Há poucos relatos na literatura sobre esta interação e seus mecanismos de controle. Assim, o objetivo deste trabalho foi o de padronizar técnicas e modelos experimentais em Piaractus mesopotamicus (pacu) e Oreochromis niloticus (tilápia-do-nilo) tornados diabéticos pela injeção de aloxana para o estudo da inflamação aguda induzida por Aeromonas hydrophila inativada. Primeiramente, foi realizada a validação de dois kits comerciais ELISA para a quantificação de insulina e do cortisol nesta espécie. Deste resultado constatou-se que a recuperação e a linearidade da insulina estiveram fora do intervalo esperado. Por outro lado, apesar do cortisol apresentar boa recuperação a linearidade mostrou-se baixa. Posteriormente, foi realizada padronização da indução de diabetes em pacus e tilápias-do-nilo. Para tanto, foram testados 8 protocolos utilizando aloxana. A dose estabelecida para ambas espécies foi de 150 mg/Kg de aloxana diluída em 2 mL de solução de citrato buffer 0,01M pH 4. Para avaliação do processo inflamatório em peixes diabéticos12 foram utilizados 360 pacus (± 110g), distribuídos em 2 grupos, diabéticos e não diabéticos. Cada grupo foi dividido em dois outros, sendo um controle, injetado com solução salina e outro injetado com A. hydrophila inativada. As avaliações da inflamação foram realizadas 1, 3, 6 e 9 horas após as injeções utilizando os seguintes parâmetros: hematócrito, hemoglobina, número de eritrócitos, CHCM, HCM, albumina, globulina, triglicerídeos, colesterol e burst respiratório. Os resultados demonstraram que nos peixes diabéticos houve diminuição de todos estes parâmetros. Maiores contagens de leucócitos, granulócitos e monócitos. Também foi verificado que as funções renais e hepáticas não foram alteradas pelo uso da aloxana e não houve diferenças nos níveis plasmáticos de lisozima, aglutinação e tiroxina. Pelos resultados acima expostos concluiu-se que a aloxana foi eficaz na indução do diabetes com preservação da função renal e hepática. Os resultados sugerem que a indução do diabetes e a inflamação experimental apresentam características adequadas para o uso deste peixe como modelo experimental.

Literature is scarce regarding the participation of the endocrine system in the development of the inflammatory process and its interaction with the pancreatic hormones. The aim of this study was to standardize experimental techniques and fish as experimental models for the study of acute inflammation induced by Aeromonas hydrophila inactivated in alloxan-diabetic Piaractus mesopotamicus (pacus). First, two commercial ELISA kits for insulin and cortisol were validated to facilitate the quantification of these hormones. However, recovery and linearity were out of the range expected for insulin and in the case of cortisol despite good recovery linearity, this was under expected. Afterwards, a study was carried out to standardize13 the use of pacus and Nile tilapia for the study of diabetes. For this, 8 protocols were tested using alloxan. The established dose for both species was 150 mg / kg of alloxan diluted in 2 mL of citrate buffer 0.01M pH 4 using benzocaine to anesthetize the animals. Finally, to evaluate the inflammatory process in diabetic fish, 360 pacus (± 110g) were used distributed into 2 groups, diabetic and non-diabetic. Each group was divided into two others, being one control, injected with saline and another one injected with inactivated A. hydrophila. Inflammation assessments were performed 1, 3, 6 and 9 hours after injections. Hematocrit, hemoglobin, number of erythrocytes, CHCM, HCM, albumin, globulin, and respiratory burst were were observed to be decreased in diabetic fish probably related to the decrease of iron found due to bacterial consumption and alloxan metabolism. However, these fish also had higher counts of leukocytes, granulocytes and monocytes, probably related to the exacerbated increase of the leukocyte adhesion in the vascular endothelium, damaging the chemotaxis. The decrease in triglycerides and cholesterol was related to the increase in energy demand due to the absence of insulin. It was also found that renal and hepatic functions were not altered by the use of alloxan. There were no differences in plasma levels of lysozyme, agglutination and thyroxine. The progressive decrease of triiodothyronine was related to the increase of lipid metabolism in order to provide energy for the development of the inflammatory reaction. We conclude that alloxan was effective in inducing diabetes with preservation of renal and hepatic function. The results suggest that diabetes induction and experimental inflammation present adequate characteristics for the use of this fish as an experimental model.

Syzygium cumini and the regeneration of insulin positive cells from the pancreatic duct / Syzygium cumini e a regeneração de células insulino-positivas a partir do ducto pancreático

Syzygium cumini is a plant that has been used in popular medicine for the treatment of insulin dependent diabetes mellitus (DMID). This study verified the effect of Syzygium cumini upon the regeneration of insulin producing cells in the pancreatic duct wall. The animals were divided into four groups, control (C), treated control (TC), diabetic control (DC) and treated diabetic (TD). An aqueous extract from Syzygium cumini bark was given by gavage in a daily dose of 1g/kg of body weight. After a thirty day period the animals were euthanized and the pancreas taken to immunohistochemical analysis. In this study, it was observed the positive staining for insulin on cells of the pancreatic duct and connective tissue in the pancreas of TD and TC animals. These results indicate that Syzygium cumini bark extract stimulates development of insulin positive cells from the pancreatic duct epithelial cells. (AU)

O Syzygium cumini é uma planta medicinal que tem sido utilizada popularmente para o tratamento da diabetes melito insulino dependente (DMID). Este estudo verificou o efeito do extrato da casca de Syzygium cumini sobre a regeneração de células insulino-positivas, a partir do ducto pancreático, no pâncreas de ratos normais e diabéticos. Os animais foram divididos em grupo controle (C), controle tratado (CT), diabético controle (DC) e diabético tratado (DT). Nos grupos tratados foi realizada a administração oral do extrato aquoso da casca de Syzygium cumini, na dose de 1g/kg de peso vivo. Após um período de 30 dias, os animais foram submetidos à eutanásia e o pâncreas retirado para análise imunohistoquímica. Neste estudo, foram visualizadas células insulino-positivas no ducto pancreático e no tecido conjuntivo próximo a ele, no pâncreas dos animais dos grupos DT e CT. Estes resultados indicam que o tratamento com o extrato da casca de Syzygium cumini na dose de 1g/kg estimula a formação de células insulino-positivas a partir das células epiteliais do ducto pancreático. (AU)

Experimental model of induction of diabetes mellitus in rats

Diabetes mellitus is a potentially morbid condition with high prevalence worldwide, thus being a major medical concern. Experimental models play an important role in understanding such a disease, which is treatable only. This study describes a rat diabetes mellitus model induced by administering a reduced dose of alloxan, thus greatly reducing the animals’ death rate.

O diabetes mellitus é uma condição mórbida da maior importância no contexto da medicina. Este artigo decreve um dos modelos de indução do diabetes mellitus com aloxano, uma das substâncias que provocam a hiperglicemia permanente em várias espécies. Com base na literatura, tem o intuito de estabelecer esse modelo como uma opção para investigar as complicações do diabetes mellitus e seus tratamentos. Tese, ainda, considerações sobre perspectivas de aplicações deste modelo, ainda pouco utilizado.

Experimental model of induction of diabetes mellitus in rats

Diabetes mellitus is a potentially morbid condition with high prevalence worldwide, thus being a major medical concern. Experimental models play an important role in understanding such a disease, which is treatable only. This study describes a rat diabetes mellitus model induced by administering a reduced dose of alloxan, thus greatly reducing the animals death rate.

O diabetes mellitus é uma condição mórbida da maior importância no contexto da medicina. Este artigo decreve um dos modelos de indução do diabetes mellitus com aloxano, uma das substâncias que provocam a hiperglicemia permanente em várias espécies. Com base na literatura, tem o intuito de estabelecer esse modelo como uma opção para investigar as complicações do diabetes mellitus e seus tratamentos. Tese, ainda, considerações sobre perspectivas de aplicações deste modelo, ainda pouco utilizado.

Caracterização de um modelo experimental de Diabetes Mellitus, induzido pela aloxana em ratos: estudo clínico e laboratorial

PURPOSE: This work aimed to determine the clinical and laboratory alterations of rat with Diabetes mellitus using alloxan endovenously. METHODS: The animals were randomly assigned to two experimental groups: Normal Control Group (G1) with 25 healty animals and Diabetic Group (G2) with 25 severe diabetic animals. They were evaluated in 5 moments (1, 3, 6, 9 and 12 months) during which the following parameters were studied: clinical evolution (body weight, water intake, food intake, and diuresis) and biochemical exams (fast glycemia, urinary glucose, glucosuria, ketonury, total cholesterol, HDL cholesterol, triglycerides and lipids). RESULTS: Alloxan 2% injection intravenously in the rat was followed by 39% death rate and also caused severe diabetes in 39% of the animals. Diabetes was characterized by progressive body weight loss, significative water intake, food intake and diuresis with blood glucose levels above 300 mg/dl, glucosuria 3+ and eventually ketonury. Diabetes doesn`t change profile a long-term of cholesterol and lipids levels. CONCLUSION: Our studies showed that alloxan causes clinical and laboratory alterations in the rat, what is typical of severe diabetes. They allow the long-term studies of diabetic.

OBJETIVO: O presente estudo teve por objetivo caracterizar as alterações clínicas e laboratoriais do rato portador de Diabetes Mellitus induzido pela administração endovenosa de aloxana. MÉTODOS: Os animais foram distribuídos, por sorteio, em dois grupos experimentais: Grupo Controle Normal (G1), constituído de 25 animais sadios, e Grupo Diabético (G2), formado por 25 animais diabéticos graves, que foram avaliados em cinco momentos (1, 3, 6, 9 e 12 meses) de seguimento, tendo sido estudados os seguintes parâmetros: evolução clínica (peso, ingestão hídrica, ingestão alimentar e diurese) e exames bioquímicos (glicemia de jejum, glicose urinária, glicosúria, cetonúria, colesterol total, colesterol HDL, triglicérides e lipídios). RESULTADOS: A injeção de aloxana 2% na via endovenosa do rato acompanhou-se de um índice de mortalidade de 39%, tendo produzido diabetes grave também em 39% dos animais. O diabetes foi caracterizado por queda progressiva do peso corporal, elevação substancial da ingestão hídrica, ingestão alimentar e da diurese, com valores glicêmicos acima de 300 mg/dl, glicosúria 3+ e, eventualmente, cetonúria. O diabetes não altera o perfil de colesterol e lípides de ratos a longo prazo. CONCLUSÃO: Nossos estudos revelam que a aloxana produz, no rato, alterações clínicas e laboratoriais características de diabetes grave, as quais possibilitam estudos a longo prazo do diabetes.

Phytochemical Analysis and hypoglycemic potential of Filago hurdwarica (Wall. ex DC.) Wagenitz in alloxan induced diabetic mice / Análise fitoquímica e potencial hipoglicemiante de Filago hurdwarica (Wall. ex DC.) Wagenitz em camundongos diabéticos induzidos por aloxana

Plants have profound therapeutic benefits, more economical treatments, fewer side effects, and a relatively cheap cost, making them a source of drugs for protective, preventative, curative, or conducive purposes and creating novel phytomedicines. Plant derived medicines are relatively safe compared to synthetic medicines. Many plants have proved to successfully aid in the treatment of diabetes including Filago hurdwarica (Wall. ex DC.) Wagenitz. The current investigations were therefore designed to assess the phytochemical, antioxidant, antidiabetic, and antihyperlipidemic activities of F. hurdwarica. The phytochemical investigations and antioxidant activities of different extracts were carried out using standard chemical tests, DPPH, and H2O2 scavenging assays. F. hurdwarica plant extract in Hydromethanolic solution were prepared by Soxhletation method and stored in refrigerator at 4°C for two days before use. Swiss Albino mice were made diabetic by a single dose of alloxan (150 mg/kg). Hydromethanolic plant extract and fractions of F. hurdwarica were screened for antidiabetic activity and given to the alloxan-induced diabetic mice at a concentration of 150-250 mg/kg of body weight in different groups of 6 diabetic mice each orally once a day for 15 days. Glibenclamide is also given to another group to as a standard drug to support the result at a dose of 10 mg/kg of body weight orally once a day for 15 days. Blood glucose levels and body weights of mice were measured on 0, 4, 7, 11 and 15th days. The study found that the extract was safe up to the dose level of 2000 mg/kg and the dose response effect of chloroform extract (150-250 mg/kg) of F. hurdwarica showed expressive antihyperglycemic effects and also improved other altered biochemical parameters associated with diabetes. The FTIR and XRD spectra demonstrated the occurrence of phenols, alcohols, alkenes, alkyl halides, ketones, and aromatic compounds and confirmed the amorphous nature of the extract. GC-MS spectral analysis showed the tentative presence of 31 phytochemical constituents in the chloroform extract of F. hurdwarica with different retention time. To conclude, the chloroform extract (250 mg/kg) of F. hurdwarica revealed considerable antioxidant, antihyperglycemic, and antihyperlipidemic potential and is safe for treating diabetes and related complications.

As plantas têm profundos benefícios terapêuticos, tratamentos mais econômicos, menos efeitos colaterais e um custo relativamente barato, tornando-as uma fonte de medicamentos para fins protetores, preventivos, curativos ou propícios e criando novos fitomedicamentos. Medicamentos derivados de plantas são relativamente seguros em comparação com medicamentos sintéticos. Muitas plantas provaram ajudar com sucesso no tratamento de diabetes, incluindo Filago hurdwarica (Wall. ex DC.) Wagenitz. As investigações atuais foram, portanto, projetadas para avaliar as atividades fitoquímicas, antioxidantes, antidiabéticas e anti-hiperlipidêmicas de F. hurdwarica. As investigações fitoquímicas e atividades antioxidantes de diferentes extratos foram realizadas usando testes químicos padrão, DPPH e ensaios de eliminação de H2O2. O extrato da planta F. hurdwarica em solução hidrometanólica foi preparado pelo método Soxhletation e armazenado em geladeira a 4 °C por dois dias antes do uso. Camundongos Swiss Albino foram tornados diabéticos por uma única dose de aloxana (150 mg/kg). Extrato de planta hidrometanólica e frações de F. hurdwarica foram rastreados quanto à atividade antidiabética e administrados aos camundongos diabéticos induzidos por aloxana em uma concentração de 150-250 mg/kg de peso corporal em diferentes grupos de 6 camundongos diabéticos cada, por via oral, uma vez ao dia por 15 dias. A glibenclamida também é administrada a outro grupo como medicamento padrão para apoiar o resultado na dose de 10 mg/kg de peso corporal por via oral uma vez ao dia por 15 dias. Os níveis de glicose no sangue e os pesos corporais dos camundongos foram medidos em 0, 4, 7, 11 e 15 dias. O estudo descobriu que o extrato era seguro até o nível de dose de 2.000 mg/kg e o efeito dose-resposta do extrato de clorofórmio (150-250 mg/kg) de F. hurdwarica mostrou efeitos anti-hiperglicêmicos expressivos e também melhorou outros parâmetros bioquímicos alterados associados com diabete. Os espectros de FTIR e DRX demonstraram a ocorrência de fenóis, álcoois, alcenos, haletos de alquila, cetonas e compostos aromáticos e confirmaram a natureza amorfa do extrato. A análise espectral por GC-MS mostrou a presença tentativa de 31 constituintes fitoquímicos no extrato clorofórmio de F. hurdwarica com diferentes tempos de retenção. Para concluir, o extrato de clorofórmio (250 mg/kg) de F. hurdwarica revelou considerável potencial antioxidante, anti-hiperglicêmico e anti-hiperlipidêmico e é seguro para o tratamento de diabetes e complicações relacionadas.

Progression of nephropathy after islet of langerhans transplantation in alloxan-induced diabetic rats

We studied the effects of islet of Langerhans transplantation (IT) on the kidney lesions of rats with alloxan-induced diabetes. Forty-five inbred male Lewis rats were randomly assigned to 3 experimental groups: group Gl included 15 non-diabetic control rats (NC), group GIT included 15 alloxan-induced diabetic rats (DC), and group III included 15 alloxan-induced diabetic rats that received pancreatic islet transplantation prepared by nonenzymatic method from normal donor Lewis rats and injected into the portal vein (IT). Each group was further divided into 3 subgroups of 5 rats which were sacrificed at 1, 3, and 6 months of follow-up, respectively. Clinical and laboratorial parameters were recorded in the mentioned periods in the 3 experimental groups. For histology, the kidneys of all rats of each subgroup were studied and 50 glomeruli and 50 tubules of each kidney were analyzed using light microscopy by two different investigators in a double blind study. The results showed progressive glomerular basement membrane thickening (GBMT), mesangial enlargement (ME), and Bowman's capsule thickening (BCT) in the 3 experimental groups throughout the follow-up. These alterations were significantly more severe in DC rats at 6 months when compared to NC rats (p 0.01). However, the degree of GBMT, ME, and BCT observed in DC rats was not statistically different from IT rats at 1, 3, and 6 months. In addition, Armanni-Ebstein lesions of the tubules (AE) and tubular lumen protein (PRO) observed in DC rats were also observed in IT rats all over the study. These lesions were never present in NC rats. We conclude that IT did not prevent progression of kidney lesions in alloxan-induced diabetic rats within 6 months after transplantation.

Níveis glicêmicos e de colesterol em ratos com Diabetes Mellitus aloxano induzido, tratados com infusão de Bauhinia candicans ou Syzygium Jambolanum

The present study verified the efficiency of two plants used in folk medicine for the reduction of hyperglycemia in diabetic people. Sixty adult male wistar rats, with body weights ranging from 220 to 240g were treated with Alloxan to induce insulin-dependent Diabetes mellitus (IDDM). Two experiments were performed. In the first, 15 rats were treated with a single dose of alloxan (40mg/kg, i.p.); while in the second experiment animals received 60mg/kg, daily for three days. Three days after the last injection, hyperglycemia was confirmed. Positive animals were allocated into 3 groups of 5 and 15 rats for experiments I and II, respectively. Group 1 (C) was the control group, receiving standard rodent feed and water ad libitum. Group 2 (TI) received rodent feed and an infusion of Syzygium jambolanum ad libitum. Group 3 (TII) received the feed and an infusion of Bauhinia candicans. Animals were treated for a period of 21 and 40 days for experiments I and II respectively. Blood was collected by retro orbital sinus puncture with animals under ether anesthesia on days 3, 9, 16, and 23 for experiment I; and days 3, 12, 24, and 40 for experiment II. At the end of both experiments, all animals were euthanized and liver and pancreas samples were collected for light microscopy. All animals, in both experiments, had blood glucose levels above 170mg% on the third day after last alloxan injection. In the first experiment, plasma glucose was lower (P 0.001) in TI as compared to C on day 23. In experiment II, plasma glucose was lower in TI when compared to C on days 16 (P 0.004) and 40 (P 0.0001). Moreover, clinical signs of IDDM like polyfagya, polydpsya were attenuated in this group. Plasma cholesterol showed a slight increase in all animals in experiment II but no differences were observed between control and treated groups. Histopathological analysis of pancreas and liver samples in the first experiment did not show marked differences between C and treated groups. However, in experiment II, 9 out of 10 pancreas samples examined from C, and 5 out of 9 samples from TII presented necrosis. Meanwhile, only 2 out of 9 pancreas samples from TI showed islet necrosis. In conclusion, the results suggest that the use of an infusion of Syzygium jambolanum instead of water is efficient in the control of hyperglycemia and reduction of clinical signs associated with IDDM. On the other hand, the use of an infusion of Bauhinia candicans has no effect over theses variables.

Este estudo verificou a eficiência de infusão de duas plantas usadas na medicina popular, Syzygium jambolanum (Sj) e Bauhinia candicans (Bc). Sessenta (60) ratos adultos, machos, da linhagem Wistar, pesando entre 220 e 240g, foram submetidos à indução de Diabetes mellitus insulino dependente (DMID) com Aloxano. O estudo foi dividido em dois experimentos. No primeiro, 15 ratos receberam a administração de Aloxano na dosagem de 40mg/kg em dose única e no segundo, 60mg/kg uma vez ao dia, durante três dias, ambos por via intraperitonial. A hiperglicemia foi confirmada no terceiro dia de cada experimento. Após esta confirmação, os animais foram divididos aleatoriamente em três grupos de cinco e quinze animais para o primeiro e segundo experimento, respectivamente. O grupo 1 (C) serviu como controle, o grupo 2 (TI) recebeu infusão de Sj "ad libitum" como fonte líquida e o grupo 3 (TII) recebeu infusão de Bc, por um período de 21 e 40 dias, para o primeiro e segundo experimento, respectivamente. A colheita de sangue foi realizada por punção do plexo venoso retro-orbitário com os animais anestesiados, nos dias 3, 9, 16 e 23 do primeiro experimento e nos dias 3, 16, 24 e 40 do segundo. Após vinte e um dias da fase de tratamento, o grupo TI do primeiro experimento apresentou marcante redução de hiperglicemia (P 0,001). Esta mesma observação foi verificada no grupo TI do segundo experimento aos dezesseis dias da fase de tratamento (P 0,004), estendendo-se até os quarenta dias (P 0,0001), quando comparado ao grupo controle. Simultaneamente, sinais clínicos de DMID, como polifagia e polidipsia foram reduzidos neste grupo. O colesterol plasmático demonstrou aumento moderado somente nos animais do segundo experimento, não sendo observado o efeito do tratamento com infusão Sj e Bc sobre a colesterolemia dos animais em estudo. No 40º dia de ambos os experimentos, os animais foram eutanasiados e foram colhidas amostras de pâncreas e fígado para avaliação histopatológica. A análise histopatológica das amostras de pâncreas e fígado do experimento I não demonstrou diferença entre os grupos tratados e o grupo C. No entanto, no experimento II, nove em dez amostras do grupo C e cinco em nove amostras do grupo TII apresentaram necrose de células das ilhotas de Langerhans do pâncreas, enquanto que somente duas das nove amostras do grupo TI apresentaram necrose de células das ilhotas de Langerhans. Os resultados obtidos neste estudo permitem concluir que o uso de infusão da planta Sj como substituto da água é eficiente no controle da hiperglicemia e redução dos sinais clínicos do DMID como polifagia e polidipsia, enquanto que o tratamento com infusão de Bc não possui o mesmo efeito.

Níveis glicêmicos e de colesterol em ratos com Diabetes Mellitus aloxano induzido, tratados com infusão de Bauhinia candicans ou Syzygium Jambolanum

The present study verified the efficiency of two plants used in folk medicine for the reduction of hyperglycemia in diabetic people. Sixty adult male wistar rats, with body weights ranging from 220 to 240g were treated with Alloxan to induce insulin-dependent Diabetes mellitus (IDDM). Two experiments were performed. In the first, 15 rats were treated with a single dose of alloxan (40mg/kg, i.p.); while in the second experiment animals received 60mg/kg, daily for three days. Three days after the last injection, hyperglycemia was confirmed. Positive animals were allocated into 3 groups of 5 and 15 rats for experiments I and II, respectively. Group 1 (C) was the control group, receiving standard rodent feed and water ad libitum. Group 2 (TI) received rodent feed and an infusion of Syzygium jambolanum ad libitum. Group 3 (TII) received the feed and an infusion of Bauhinia candicans. Animals were treated for a period of 21 and 40 days for experiments I and II respectively. Blood was collected by retro orbital sinus puncture with animals under ether anesthesia on days 3, 9, 16, and 23 for experiment I; and days 3, 12, 24, and 40 for experiment II. At the end of both experiments, all animals were euthanized and liver and pancreas samples were collected for light microscopy. All animals, in both experiments, had blood glucose levels above 170mg% on the third day after last alloxan injection. In the first experiment, plasma glucose was lower (P 0.001) in TI as compared to C on day 23. In experiment II, plasma glucose was lower in TI when compared to C on days 16 (P 0.004) and 40 (P 0.0001). Moreover, clinical signs of IDDM like polyfagya, polydpsya were attenuated in this group. Plasma cholesterol showed a slight increase in all animals in experiment II but no differences were observed between control and treated groups. Histopathological analysis of pancreas and liver samples in the first experiment did not show marked differences between C and treated groups. However, in experiment II, 9 out of 10 pancreas samples examined from C, and 5 out of 9 samples from TII presented necrosis. Meanwhile, only 2 out of 9 pancreas samples from TI showed islet necrosis. In conclusion, the results suggest that the use of an infusion of Syzygium jambolanum instead of water is efficient in the control of hyperglycemia and reduction of clinical signs associated with IDDM. On the other hand, the use of an infusion of Bauhinia candicans has no effect over theses variables.

Este estudo verificou a eficiência de infusão de duas plantas usadas na medicina popular, Syzygium jambolanum (Sj) e Bauhinia candicans (Bc). Sessenta (60) ratos adultos, machos, da linhagem Wistar, pesando entre 220 e 240g, foram submetidos à indução de Diabetes mellitus insulino dependente (DMID) com Aloxano. O estudo foi dividido em dois experimentos. No primeiro, 15 ratos receberam a administração de Aloxano na dosagem de 40mg/kg em dose única e no segundo, 60mg/kg uma vez ao dia, durante três dias, ambos por via intraperitonial. A hiperglicemia foi confirmada no terceiro dia de cada experimento. Após esta confirmação, os animais foram divididos aleatoriamente em três grupos de cinco e quinze animais para o primeiro e segundo experimento, respectivamente. O grupo 1 (C) serviu como controle, o grupo 2 (TI) recebeu infusão de Sj "ad libitum" como fonte líquida e o grupo 3 (TII) recebeu infusão de Bc, por um período de 21 e 40 dias, para o primeiro e segundo experimento, respectivamente. A colheita de sangue foi realizada por punção do plexo venoso retro-orbitário com os animais anestesiados, nos dias 3, 9, 16 e 23 do primeiro experimento e nos dias 3, 16, 24 e 40 do segundo. Após vinte e um dias da fase de tratamento, o grupo TI do primeiro experimento apresentou marcante redução de hiperglicemia (P 0,001). Esta mesma observação foi verificada no grupo TI do segundo experimento aos dezesseis dias da fase de tratamento (P 0,004), estendendo-se até os quarenta dias (P 0,0001), quando comparado ao grupo controle. Simultaneamente, sinais clínicos de DMID, como polifagia e polidipsia foram reduzidos neste grupo. O colesterol plasmático demonstrou aumento moderado somente nos animais do segundo experimento, não sendo observado o efeito do tratamento com infusão Sj e Bc sobre a colesterolemia dos animais em estudo. No 40º dia de ambos os experimentos, os animais foram eutanasiados e foram colhidas amostras de pâncreas e fígado para avaliação histopatológica. A análise histopatológica das amostras de pâncreas e fígado do experimento I não demonstrou diferença entre os grupos tratados e o grupo C. No entanto, no experimento II, nove em dez amostras do grupo C e cinco em nove amostras do grupo TII apresentaram necrose de células das ilhotas de Langerhans do pâncreas, enquanto que somente duas das nove amostras do grupo TI apresentaram necrose de células das ilhotas de Langerhans. Os resultados obtidos neste estudo permitem concluir que o uso de infusão da planta Sj como substituto da água é eficiente no controle da hiperglicemia e redução dos sinais clínicos do DMID como polifagia e polidipsia, enquanto que o tratamento com infusão de Bc não possui o mesmo efeito.

Role of metabolic control on diabetic nephropathy

OBJECTIVE: The aim of this investigation was studying the influence of glucose metabolic control on diabetic nephropathy. The authors observed the effect of acarbose, insulin, and both drugs on the metabolic control and development of mesangial enlargement of kidney glomeruli in alloxan-diabetic rats. METHODS: Five groups of Wistar rats were used: normal rats (N), non-treated alloxan-diabetic rats (D), alloxan-diabetic rats treated with acarbose (AD), alloxan-diabetic rats treated with insulin (ID), and alloxan-diabetic rats treated with insulin plus acarbose (IAD). The following parameters were evaluated: body weight; water and food intake; diuresis; blood and urine glucose levels; and the kidney lesions: mesangial enlargement and tubule cell vacuolization. Renal lesions were analysed using a semi-quantitative score 1, 3, 6, 9, and 12 months after diabetes induction. RESULTS: Diabetic rats showed a marked increase of glycemia, urinary glucose levels, diuresis, water and food intake, and weight loss, while the treated diabetic rats showed significant decreased levels of these parameters. The most satisfactory metabolic control was that of diabetic rats treated with acarbose + insulin. There was a significant mesangial enlargement in diabetic rats compared to normal rats from the third up to the 12th month after diabetes induction, with a significant difference between the animals treated with acarbose + insulin and non-treated diabetic rats. A difference between the animals treated with acarbose or insulin alone and non-treated diabetics rats was not seen. CONCLUSIONS: The authors discuss the results stressing the role of diabetic metabolic control in the prevention of diabetic nephropathy.

OBJETIVO: Os autores relatam a influência do controle metabólico do diabetes, experimentalmente induzido no rato, sobre a nefropatia diabética. Eles observaram o efeito da insulina, da acarbose, um inibidor da glicosidase, e de dois agentes combinados sobre o controle metabólico e o desenvolvimento da expansão mesangial de glomérulos renais, no diabetes induzido pela aloxana no rato. MÉTODOS: Usando 5 grupos de ratos Wistar assim definidos: Normal(N), diabéticos não-tratados (D), diabéticos tratados com acarbose (AD); diabéticos tratados com insulina (ID) e diabéticos tratados com insulina associada à acarbose (IAD) foram avaliados os seguintes parâmetros: peso corporal, ingestão alimentar, ingestão hídrica, diurese, níveis de glicose sanguínea e urinária e as lesões renais: alargamento mesangial e vacuolização de células tubulares, usando contagem semi-quantitativa 1, 3, 6, 9 e 12 meses após a indução do diabetes. RESULTADOS: Houve acentuado aumento da glicemia, dos níveis de glicose na urina, da diurese, da ingestão hídrica e alimentar, e progressiva perda de peso nos ratos diabéticos, enquanto que os ratos diabéticos tratados exibiram melhora significativa destes parâmetros, sendo os ratos tratados com insulina + acarbose os que apresentaram controle metabólico mais satisfatório. Houve um significativo alargamento mesangial nos ratos diabéticos quando comparado ao observado nos ratos normais, desde o 3º até o 12º mês após a indução do diabetes, sendo observada diferença significativa entre os animais tratados com acarbose + insulina e os ratos diabéticos não-tratados. Não houve diferença significativa entre os animais tratados somente com acarbose ou com insulina quando comparados com ratos diabéticos não-tratados. CONCLUSÃO: Os autores discutem os resultados abordando o papel do controle metabólico do diabetes na prevenção da nefropatia diabética.

Caracterização de um modelo experimental de neuropatia em ratos diabéticos induzidos pela aloxana

One-hundred male norvegicus rats, approximately 3-months old, were randomly assigned to two experimental groups: Control Group (CG) included 50 non-diabetic control rats and Diabetic Group (DG) included 50 alloxan untreated-diabetic rats. Each group was further divided into 5 subgroups of 10 rats and sacrificed at 1, 3, 6, 9, and 12 months of follow-up, respectively. Clinical (body weight, water and food intake and urine output) and laboratory parameters (blood glucose, urinary glucose and insulin) were documented in all moments of evaluation. A segment of the sciatic nerve was taken from each animal in both groups for light and eletron microscopy. Significant clinical and laboratory changes (P 0.01), compatibles with severe diabetes, were observed in all animals of DG beginning at 4 th day after diabetes induction. There were no significant changes in the number of myelinic fibers and of glycogen granules in DG rats when compared with CG rats at 1, 3, and 6 months of follow-up. However, DG rats presented a significantly decreased number of myelinic fibers, with increase of the number of smaller myelinic fibers, when compared with CG rats (P 0.05) at 9 and 12 months of follow-up. Intra-axonal glycogen granules were also more evident in DG rats in these periods. No difference was observed between the two experimental groups in the number of unmyelinated fibers. There was also no structural difference in both groups in the intra-axonal and endoneural spaces, in the myelin sheath or in the Schwann cells all over the study.

Cem ratos norvégicus, machos, com aproximadamente 3 meses de idade foram distribuídos por sorteio em 2 grupos experimentais: Grupo Controle (GC): com 50 ratos sadios, não diabéticos e Grupo Diabético (GD): com 50 ratos diabéticos, induzidos pela aloxana, sem qualquer tratamento. Cada grupo foi dividido em 5 subgrupos com 10 ratos cada e sacrificados com 1, 3, 6, 9 e 12 meses de seguimento, respectivamente. Parâmetros clínicos (peso, ingestão hídrica e alimentar, e diurese) e laboratoriais (glicemia, glicose urinária e insulina) foram documentados em todos os momentos de avaliação. Um segmento do nervo ciático foi obtido de cada animal, em ambos os grupos, para estudo à MO. e ME. Alterações clínicas e laboratoriais significativas (P 0,01), compatíveis com diabetes grave, foram observadas em todos os animais do GD a partir do 4o dia após a indução. Ratos de ambos os grupos apresentaram alterações no número de fibras mielínicas e nos depósitos intraaxonais de glicogênio que não diferiram, estatisticamente, aos 1, 3 e 6 meses de seguimento. Entretanto, aos 9 e 12 meses, ratos do GD apresentaram diminuição significativa no número de fibras mielínicas, com aumento do número de fibras mielínicas de menor calibre, quando comparados com ratos do GC (P 0,05). Grânulos de glicogênio intraaxonais também foram mais acentuados em ratos do GD no 9o e 12o mês de seguimento. Não foram observadas diferenças na densidade de fibras amielínicas ou alterações ultraestruturais significativas entre os dois grupos, em relação aos espaços intraaxonais e endoneurais, bainhas de mielina e células de Schwann durante todo o estudo.