Improvement of bone repair in diabetic rats subjected to 780 nm low-level laser therapy

To investigate the effect of low-level laser therapy on bone healing in diabetic rats. METHODS: Bone cavities (19 mm diameter) were performed in the femur of 72 alloxan-induced diabetic rats, which were assigned into four groups: CTR (non-diabetic control), DBT (diabetic) CTRL (non-diabetic irradiated) and DBTL (diabetic irradiated). Low-level laser therapy was performed every 48h for seven days. Animals were euthanized at seven, 18 and 30 days. Alkaline phosphatase serum levels and bone repair were analyzed. RESULTS: Low-level laser therapy significantly increased alkaline phosphatase in at seven and 18 days (p 0.001), and improved bone healing at seven (p 0.01), 18 (p 0.05) and 30 (p 0.01) in diabetic animals. In addition, bone healing in irradiated diabetic group was statistically similar to control group at 30 days (p>0.05). CONCLUSION: Low-level laser therapy increased the serum levels of alkaline phosphatase and improved bone healing in alloxan-induced diabetic rats.(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)

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)

Anastomotic healing in ileum and colon of alloxan-induced diabetic rats / Cicatrização de anastomoses realizadas no íleo e cólon de ratos diabéticos induzidos pela aloxana

PURPOSE: To investigate if diabetes mellitus may alter breaking strength (BS) and collagen content in ileum and colon anastomoses in rats. METHODS: Three-hundred Wistar rats were randomly assigned to 5 experimental groups, 60 per group: normal controls surgically manipulated (G1); normal controls submitted to ileum (G2) and colon (G3) anastomotic construction; diabetic rats submitted to ileum (G4) and colon (G5) anastomotic construction. Each group was further divided into 6 subgroups with 10 rats each for sacrifice at 0, 4, 7, 14, 21, and 30 days after surgery. All surgical procedures were performed 3 months after alloxan diabetes induction. BS was measured in all intestinal anastomoses. Fragments of ileum and colon anastomoses were taken for hydroxyproline concentration (HP) and total tissue protein (TP) dosages. RESULTS: Anastomotic BS was significantly decreased (P<0.05) in ileum and colon of G4 and G5 diabetic groups up to 7 and 14 days after surgery, respectively, compared with G2 and G3 normal control groups. Anastomotic HP and TP content did not significantly differ between diabetic and normal control operated groups in ileum or colon at all evaluation times. CONCLUSION: Experimental diabetes leads to impaired intestinal anastomotic strength during early surgical wound repair, but does not appear to be implicated with collagen synthesis capacity.(AU)

OBJETIVO: Investigar se o diabetes mellitus pode alterar a força de ruptura (FR) e o conteúdo de colágeno em anastomoses realizadas no íleo e cólon de ratos. MÉTODOS: 300 ratos Wistar foram distribuídos por sorteio em 5 grupos experimentais com 60 animais cada: controle normal manipulado cirurgicamente (G1); normais controles submetidos a anastomoses no íleo (G2) e cólon (G3); ratos diabéticos submetidos a anastomoses no íleo (G4) e cólon (G5). Cada grupo foi dividido em 6 subgrupos com 10 ratos cada para sacrifícios com 0, 4, 7, 14, 21 e 30 dias após as operações. Os procedimentos cirúrgicos foram realizados 3 meses após a indução do diabetes com aloxana. A FR foi medida em todas anastomoses intestinais. Fragmentos de anastomoses do íleo e cólon foram retirados para dosagens de hidroxiprolina (HP) e proteína tecidual total (PT). RESULTADOS: A FR teve significante redução (P<0,05) nos grupos diabéticos G4 e G5, até 7 e 14 dias após a operação, respectivamente, quando comparada à observada nos grupos controles G2 e G3. Não foram observadas diferenças significantes nas dosagens de HP e PT em ratos diabéticos e controles, tanto operados no íleo como no cólon, em todos os momentos de avaliação. CONCLUSÃO: O diabetes conduz a alterações da força de ruptura de anastomoses intestinais durante a fase inicial da reparação da ferida cirúrgica, porém, este fato parece não estar relacionado à capacidade de sintetizar colágeno.(AU)

Long term evaluation of functional and morphological bladder alterations on alloxan-induced diabetes and aging: experimental study in rats / Avaliação funcional e morfológica tardia de alterações na bexiga secundárias ao diabetes induzido por aloxano e no envelhecimento: estudo experimental em ratos

PURPOSE: to evaluate structural and functional effects of Alloxan- induced diabetes and aging on bladder of rats. METHODS: evaluations were performed in three groups: A - 8 weeks of age, B - 44 weeks of age, C - 44 weeks of age with alloxan-induced diabetes. Muscle layer thickness, extracellular matrix fibrosis and collagen were quantified on digital images of bladder samples. Cystometric evaluations before surgical vesical denervation (SVD), included maximum cystometric capacity (MCC), maximum bladder pressure (MBP), bladder contraction frequency (VCF), duration of bladder contraction (DC), threshold pressure (TP) and bladder compliance (BC). After SVD, maximum cystometric capacity (MCC), BC and maximum urethral closing pressure (MUCP) were also measured. RESULTS: Reduced extracellular matrix fibrosis concentration and contraction strength were found in the bladders of group C. Before SVD, bladder compliance was not different between groups. Alterations were observed in MCC after SVD. CONCLUSIONS: We did not notice smooth muscle hypertrophy in Alloxan-induced diabetic rats after 44 weeks. There was alteration in the total and relative amount of fibrosis and collagen. The cystometric studies support the idea that this morphological alterations are important to determine the different bladder functional patterns found in the aging and the Alloxan-induced diabetic animals.(AU)

OBJETIVOS: avaliar alterações estruturais e funcionais da bexiga de ratos machos, associadas ao diabetes induzido por aloxano e ao envelhecimento. MÉTODOS: três grupos de animais: A - 8 semanas de idade; B- 44 semanas de idade; C - 44 semanas de idade com diabetes induzido por aloxano, foram avaliados. Realizadas medidas de espessura da camada muscular, fibrose de matriz extracelular e quantidade de colágeno, através de análise de imagem digital dos tecidos. Realizados também testes cistométricos, antes da desnervação vesical cirúrgica (DVC), para avaliar capacidade vesical (CV), intensidade máxima de contração vesical (IMCV) e complacência vesical. Após a DVC, foram avaliadas capacidade vesical após a desnervação (CVAD), complacência vesical (CV) e pressão de perda uretral (PPU). RESULTADOS: não foi observada hipertrofia da camada muscular nas bexigas; houve diminuição da concentração de fibrose da matriz extracelular e diminuição da força contrátil, e aumento da capacidade vesical no grupo C. CONCLUSÕES: a atrofia da camadas muscular da bexiga esta relacionada ao diabetes induzido por aloxano. O envelhecimento, como fenômeno isolado, provoca alterações nos parâmetros funcionais, porém associado ao diabetes, gera alterações na IMCV, CV e CVAD. Existe correlação entre alterações estruturais e funcionais nos animais diabéticos após a desnervação.(AU)

Reduction of podocytes number in late diabetic alloxan nephropathy: prevention by glycemic control / Redução do número de podócitos na fase tardia da nefropatia diabética aloxânica. Prevenção pelo controle glicêmico

PURPOSE: To determine podocyte number and GBM thickness in diabetic rats either under glycemic control or without glycemic control at 6 and 12 months after diabetes induction. METHODS: 100 wistar rats weighing 200-300g were divided into 6 groups: Normal group (N6 and N12- 25 rats); Diabetic group (D6 and D12- 25 rats), diabetic treated group ( DT 6 and DT 12- 25 rats) on insulin 1,8- 3,0 IU/Kg associated with acarbose (50mg to 100g of food) daily mixed in chow. Alloxan was injected intravenously in a dose of 42 mg/Kg of weight. Body weight, waterintake, 24-h diuresis, glycemia and glucosuria were determined before induction, 7 and 14 days after induction and monthly thereafter. Treatment started at day 14. Three groups were sacrificed at 6 months (N6,D6, DT6) and 3 groups at 12 months (N12, D12, DT12) with the renal tissue being prepared for electron microscopy. RESULTS: Glycemia in DT6ùand in DT12 was significantly different from that in D6 and D12 rats and similar to that in N6 and N12 animals. The number of podocytes in DT6 was not different from that in N6 and D6 (median = 11); the number of podocytes in DT12 (median = 11) differed from that in D12 (median = 8), but not from that in N12 (median = 11). GBM thickness in D6 (0.18 micrometers) was lower than in D12 (0.29 micrometers); while in DT6 (0.16 micrometers) it was lower than in D6 (0.18 micrometers). In DT12 (0.26 micrometers), it was lower than in D12 (0.29 micrometers). CONCLUSION: The control of hyperglycemia prevented GBM thickening in early and late (12 mo) alloxan diabetic nephropathy and podocyte number reduction.(AU)

OBJETIVO: Avaliar o número de podócitos e espessamento da membrana basal glomerular (MBG) em ratos diabéticos com e sem controle glicêmico com 6 e 12 meses da indução. MÉTODOS: 100 ratos Wistar com 200-300g compuseram 6 grupos: Normal (N6, N12 - 25 animais) Diabético (D6,D12 - 25 animais) e diabético tratado com insulina 1,8 a 3,0 U/Kg e acarbose misturada a ração (50g para cada 100g de ração) (DT6 e DT12 - 25 animais). Aloxana foi ministrada via endovenosa na dose de 42mg/Kg. Peso, ingestão hídrica e diurese de 24 horas e glicemia e glicosúria foram determinados antes da inoculação, 7 e 14 dias após e mensalmente. No 14ª dia foi iniciado o tratamento. Três grupos de animais (N6, D6 e DT6) foram sacrificados no 6º mês e três grupos (N12, D12 e DT12), no 12ª mês sendo o tecido renal processado para estudo à microscopia eletrônica. RESULTADOS: A glicemia dos animais DT6 e DT12 diferiram significativamente, dos ratos D6 e D12, e não diferiram dos grupos N6 e N12. O número de podócitos do grupo DT6 não diferiu de N6 e D6 (mediana=11); o número de podócitos de DT12 (mediana=11) diferiu de D12 (mediana=8) e não diferiu de N12 (mediana=11). O espessamento da MBG de D6 (0,18 micrômetros) foi menor que D12 (0,29 micrômetros); de DT6 (0,16 micrômetros) foi menor que D6 (0,18 micrômetros) e de DT12 (0,26 micrômetros) foi menor que D12 (0,29 micrômetros). CONCLUSÃO: O controle da hiperglicemia preveniu o espessamento da MBG na nefropatia diabética aloxânica precoce (6 meses) e tardia (12 meses), e a diminuição do número de podócitos.(AU)

Viability of a random pattern dorsal skin flap, in diabetic rats / Viabilidade do retalho cutâneo randômico dorsal em ratos diabéticos

OBJETIVO: Avaliar a viabilidade do retalho cutâneo randômico dorsal em ratos experimentalmente induzidos ao diabetes mellitus. MÉTODOS: Foram utilizados 30 ratos Wistar, adultos, machos, distribuídos em 2 grupos: I controle submetidos somente ao retalho cutâneo e II experimental submetidos ao retalho cutâneo após 10 dias da indução do diabetes mellitus com aloxano. RESULTADOS: O grupo controle teve 36,39% e o grupo experimental 52,06% de média de área de necrose. CONCLUSAO: A viabilidade do retalho cutâneo randômico dorsal foi menor no rato diabético do que no rato normal. (AU)

PURPOSE: Evaluation of the viability of a random pattern dorsal skin flap, in rats with experimentally induced diabetes mellitus.METHODS: Thirty adult, male, Wistar EPM rats were distributed, at random, in two groups: I - Control (flap elevation) and II - Experimental (flap elevation ten days after alloxan induced diabetes ).RESULTS: The mean areas of necrosis in the different groups were 36.4% (Control) and 52.1% (Experimental).CONCLUSION: The random pattern dorsal skin flap was less viable in the diabetic rats.

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)