الملخص
We compared the effect of the treatment with strength training (ST) and raloxifene (RALOX) on bone weight, blood glucose, lipid, and antioxidant profile in ovariectomized rats. Twenty-four Wistar rats were distributed into four groups: ovariectomy + VEHICLE (control); ovariectomy + RALOX; ovariectomy + ST; ovariectomy + RALOX + ST. Thirty days after ovariectomy, the animals underwent the treatment with RALOX (750 µcg day-1) and/or ST (three sessions week-1). Thirty days after, all groups were scarified, tibia and femur were weighed, and the blood was collected for analysis of the lipid profile, glucose, and antioxidants catalase (CAT) and glutathione (GSH). The ST group showed greater femur weight (0.82 ± 0.18 g) and RALOX + ST had greater tibia weight (0.61± 0.17 g) than CONTROL with femur weight of 0.65 ± 0.08 g and tibia of 0.49 ± 0.08 g with no differences between treatments (p > 0.05). ST group showed significantly higher catalase (181.7 ± 15.4 µM g-1) compared to the other groups. In contrast, the GSH value was lower in ST group (89.2 ± 8.1 µM g-1) compared to RALOX (175.9 ± 17.1 µM g-1) and RALOX + ST (162.8 ± 12.1 µM g-1), but the values of these two groups did not differ from CONTROL(115.3 ± 21.1 µM g-1). Total cholesterol did not differ between groups (p > 0.05), but exercise alone(54.3 ± 2.5 mg dL-1) or with RALOX (53.0 ± 1.5 mg dL-1) resulted in higher HDL cholesterol than CONTROL (45.5 ± 2.5 mg dL-1). Only RALOX+ST presented lower glucose (140.3 ± 9.7 mg dL-1) values than CONTROL (201.7 ± 30.6 mg dL-1). In conclusion, ST promotes similar benefits on bone and metabolic parameters compared to pharmacological treatment in ovariectomized rats.(AU)
الموضوعات
Animals , Female , Rats, Wistar/physiology , Raloxifene Hydrochloride/adverse effects , Resistance Training/adverse effects , Blood Glucose/analysis , Ovariectomy/veterinary , Lipid Metabolism , Antioxidantsالملخص
Purpose: Remote ischemic preconditioning (RIPC) confers cardioprotection against ischemia reperfusion (IR) injury. However, the precise mechanisms involved in RIPC-induced cardioprotection are not fully explored. The present study was aimed to identify the role of melatonin in RIPC-induced late cardioprotective effects in rats and to explore the role of H2 S, TNF-α and mitoKATP in melatoninmediated effects in RIPC. Methods: Wistar rats were subjected to RIPC in which hind limb was subjected to four alternate cycles of ischemia and reperfusion of 5 min duration by using a neonatal blood pressure cuff. After 24 h of RIPC or ramelteon-induced pharmacological preconditioning, hearts were isolated and subjected to IR injury on the Langendorff apparatus. Results: RIPC and ramelteon preconditioning protected the hearts from IR injury and it was assessed by a decrease in LDH-1, cTnT and increase in left ventricular developed pressure (LVDP). RIPC increased the melatonin levels (in plasma), H2 S (in heart) and decreased TNF-α levels. The effects of RIPC were abolished in the presence of melatonin receptor blocker (luzindole), ganglionic blocker (hexamethonium) and mitochondrial KATP blocker (5-hydroxydecanoic acid). Conclusion: RIPC produce delayed cardioprotection against IR injury through the activation of neuronal pathway, which may increase the plasma melatonin levels to activate the cardioprotective signaling pathway involving the opening of mitochondrial KATP channels, decrease in TNF-α production and increase in H2 S levels. Ramelteon-induced pharmacological preconditioning may also activate the cardioprotective signaling pathway involving the opening of mitochondrial KATP channels, decrease in TNF-α production and increase in H2 S levels.
الموضوعات
Animals , Rats , Troponin/physiology , Cardiotonic Agents , Ischemic Preconditioning , Melatonin/analysis , Myocardial Infarction/veterinary , Enzyme-Linked Immunosorbent Assay/veterinary , Rats, Wistar/physiology , Mitochondriaالملخص
The objective of this study was to investigate the effects of a gel formulation from the association of Plectranthus neochilus and Cnidoscolus quercifolius on tissue repair in cutaneous wounds in rats. A surgical wound was induced in 35 Wistar rats and treated according to group: G1 - commercial phytotherapeutic gel; G2 - Carbopol gel 1%; G3, 4, 5 - gel formulation from Boldo-gambá and Favela (FGBF) at 2.5%, 5%, and 10%, respectively. 1ml of the product was applied topically daily, for 14 days. Macroscopic evaluation of the wound showed inflammation, granulation, and epithelization in all groups. The FGBF 2.5% group showed greater angiogenic potential. There was a significant difference between the surgical area of the wounds treated with FGBF 2.5%, 5%, or 10% compared to the group with the commercial phytotherapeutic gel. On histomorphometry of the skin, there were reepithelization of the epidermis and superficial dermis, longitudinal collagen fibers, fibroblasts, and blood vessels, and in the deeper dermis, fibroblasts, transverse and longitudinal collagen fibers, blood vessels, and inflammatory cells. The 2.5% formulation had the greatest increase in fibroblast proliferation and most intense collagenization on day 14 of treatment.(AU)
Este trabalho objetivou investigar os efeitos de uma formulação em gel da associação da Plectranthus neochilus e da Cnidoscolus quercifolius no processo de reparação tecidual em feridas cutâneas de ratos. Foi induzida uma ferida cirúrgica em 35 ratos Wistar, sendo tratadas de acordo com os grupos: G1 - fitoterápico comercial; G2 - gel de carbopol 1%; G3, G4 e G5 - formulação gel boldo-gambá mais favela (FGBF) 2,5%, 5% e 10%, respectivamente. Aplicou-se 1mL do produto, via tópica, diariamente, durante 14 dias. Na avaliação macroscópica das feridas, verificou-se inflamação, granulação e epitelização em todos os grupos. O grupo FGBF 2,5% apresentou maior potencial angiogênico. Houve diferença significativa entre as áreas cirúrgicas das feridas tratadas com os FGBF 2,5%, 5% ou 10%, comparados ao grupo com o gel fitoterápico comercial. Na histomorfometria da pele, observou-se reepitelização da epiderme e da derme superficial, fibras colágenas longitudinais, fibroblastos e vasos sanguíneos e, na derme profunda, fibroblastos, fibras colágenas transversais e longitudinais, vasos sanguíneos e células inflamatórias. A formulação a 2,5% teve o maior aumento na proliferação de fibroblastos e mais intensa colagenização no dia 14 de tratamento.(AU)
الموضوعات
Animals , Rats , Wound Healing , Wounds and Injuries/therapy , Jatropha/chemistry , Plectranthus/chemistry , Plants, Medicinal , Wounds and Injuries/veterinary , Rats, Wistar/physiology , Phytotherapy/veterinaryالملخص
Cicatrização de ferida é um processo dinâmico, que tem por objetivo restaurar a continuidade do tecido lesionado. No entanto, em alguns casos, é necessário favorecer condições adequadas para viabilizar o processo fisiológico. Neste estudo foram utilizados ratos Wistar, divididos aleatoriamente entre cinco grupos, com 12 animais cada, sendo eles: grupo P (Bidens pilosa L.), grupo mel, grupo Co1 (pomada comercial alopática), grupo Co2 (pomada comercial homeopática) e grupo CT (controle). As lesões foram geradas por incisão com punch de 8mm, sendo tratadas diariamente de forma tópica. Foram eutanasiados quatro animais por grupo, no terceiro, sétimo e 14º dias do experimento, e o material coletado foi armazenado em formalina 10% e encaminhado para processamento histológico. Posteriormente, realizou-se a contagem de leucócitos mononucleares, fibroblastos e neovasos e avaliou-se a arquitetura de fibras colágenas. Os resultados da contagem foram analisados pela ANOVA, seguida pelo teste de Tukey (P<0,05). O modelo experimental proposto neste estudo demonstrou que todos os tratamentos apresentaram potencial cicatrizante, com exceção do mel. A aplicação tópica do creme do extrato de Bidens pilosa L. a 10% apresentou melhor perfil anti-inflamatório; a pomada alopática apresentou boa aderência à superfície da lesão e a pomada homeopática, grande potencial angiogênico, com menor tempo de cicatrização.(AU)
Wound healing is a dynamic process that aims to restore the continuity of injured tissue. However, in some cases it is necessary to favor adequate conditions to enable the physiological process. Wistar rats were randomly divided into 5 groups with 12 animals each, namely: group P (Bidens pilosa L.), group honey, group Co1 (commercial allopathic ointment), group Co2 (commercial homeopathic ointment) and group CT (control). The lesions were generated by an 8mm punch incision and were treated topically daily. Four animals per group were euthanized on the 3rd, 7th and 14th day of the experiment and the collected material was stored in 10% formalin and sent for histological processing, after which mononuclear, fibroblasts and neovascular leukocytes were counted and collagen fiber architecture was evaluated. Counting results were analyzed by ANOVA, followed by Tukey test (p <0.05). The experimental model proposed in this study showed that all treatments had healing potential, except honey. The topical application of 10% Bidens pilosa L. extract cream showed the best anti-inflammatory profile; Allopathic ointment showed good adhesion to the surface of the lesion and homeopathic ointment showed great angiogenic potential with shorter healing time.(AU)
الموضوعات
Animals , Rats , Ointments/therapeutic use , Skin/injuries , Bidens/chemistry , Honey , Wound Healing/drug effects , Wounds and Injuries/therapy , Homeopathic Remedy , Collagen , Rats, Wistar/physiology , Phytotherapeutic Drugs , Fibroblastsالملخص
No presente estudo, foram analisados os efeitos do estanozolol, associado ou não à atividade física, sobre o hemograma, o peso ponderal, a ingestão líquida e sólida, a urinálise, a expressão do VEGF-A renal e o glicogênio hepático, além da histopatologia hepática e renal em ratos Wistar. Foram utilizados 32 ratos Wistar, machos, jovens, separados em quatro grupos: GC (grupo controle); GCE (grupo controle-exercício); GT (grupo tratamento-esteroide); GTE (grupo tratamento-esteroide-exercício). Os animais dos grupos GT e GTE (n=16) foram submetidos a injeções subcutâneas, cinco dias/semana, durante 30 dias, na concentração de 5mg/kg de estanozolol diluído em 1mL de óleo de gergelim, utilizado como veículo. A natação foi definida como exercício físico. Houve aumento no peso dos animais submetidos ao estanozolol e ao exercício a partir da terceira semana de uso e aumento da excreção urinária a partir da quinta semana; os demais parâmetros da urinálise foram semelhantes entre os grupos. O uso de estanozolol associado ou não à atividade física promoveu redução da expressão do VEGF-A nos rins e do glicogênio hepático, além de alterações histopatológicas nesses órgãos. Quanto à hematologia, houve uma diminuição dos leucócitos no GTE em relação aos grupos GT e GCE. Quanto aos linfócitos, houve um aumento no GT e uma diminuição no GTE, e, em relação ao número de plaquetas, houve diminuição no GTE quando comparado ao GT e ao GCE Assim, conclui-se que estanozolol na dose de 5,0mg/kg causa alterações renais e hepáticas em ratos Wistar, podendo levar à falência dos rins e do fígado.(AU)
The goal of this study was to determine the effect of stanozolol (ST) on kidney and liver of Wistar rats. Thirty-two male animals were divided into the following four groups: control group (CG); Control group-exercise (GCE); Group-steroid treatment (GT); Group treatment-steroid-exercise (GTE). Swimming was defined as exercise. The animals GT and GTE was submitted to subcutaneous injections, five days/week for 30 days, at a concentration of 5mg/kg ST diluted in 1mL/kg of sesame oil. The results showed an increase in weight gain in all animals submitted to ST and exercise from the 3rd week of use and increase in urinary excretion from the 5th week and the other urinalysis parameters were similar. The ST associated or not with physical activity reduced VEGF-A expression in the kidneys and hepatic glycogen, as well as histopathological changes in these organs. Regarding hematology, there was a decrease in leukocytes in the GTE. As for lymphocytes there was an increase in GT and a decrease in GTE, and in relation to the number of platelets, there was a decrease in GTE. In conclusion, the administration of stanozolol at 5.0mg/kg caused a structural change of kidney and liver in treated animals.(AU)
الموضوعات
Animals , Rats , Stanozolol/administration & dosage , Swimming , Kidney/anatomy & histology , Liver/drug effects , Rats, Wistar/physiology , Anabolic Agents/administration & dosage , Kidney Function Tests/veterinaryالملخص
Hexavalent chromium [Cr (VI)] is a metal utilized in different industries and consequently disposed in the environment. It is a toxic substance and its reduction to trivalent Cr [Cr (III)] generates intermediates, which are responsible for the oxidation of molecules, and cause the oxidative stress. Therefore, the aim of this study was to evaluate if Cr (VI) could induce oxidative stress in Wistar rats. In this study, Wistar rats were chronically exposed to 25 and 50 ppm of potassium dichromate in drinking water for 30 days. The levels of Cr were evaluated in the blood and tissues (liver, kidneys, and lungs). Oxidative stress was determined in the liver, kidneys, and lungs and was evaluated by DFCH, TBA-RS and carbonyl test. Antioxidant enzymes were evaluated through catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. Regarding the results, Cr concentration was significantly elevated in all tissues, however, it was lower in the lungs. In relation to the oxidative stress parameters, there was a significant increase of DCFH levels in the kidneys and carbonyls in liver and kidneys. Regarding the antioxidant enzymes, SOD was decreased in all organs and GPx was diminished in the kidneys. These data indicated that Cr (VI) could induce oxidative stress in the kidneys and liver due to an imbalance between oxidative and antioxidant parameters. The lungs were little affected, possibly by the lowest chromium accumulation.
الموضوعات
Animals , Rats , Chromium , Oxidative Stress , Rats, Wistar/physiologyالملخص
PURPOSE:To analyze the physiological and biochemical measurements before, during and after pregnancy of healthy rats.METHODS:Wistar adult females rats (n=8) were weighed and blood samples were obtained before, during and after pregnancy for biochemical determinations, chow intake, water consumption and milk production were evaluated. At day 10 postpartum, the rats were killed for weighing of organs and adipose tissues.RESULTS: The results showed increase in body weight, serum insulin and ingestion of water and chow. At day 17 pregnancy, presented normal values in the OGTT. At days 7, 14 and 20 of pregnancy, there was increase in triglyceride levels. At term pregnancy, there was weight gain due to fetal growth. In the postpartum period presented reduced blood glucose levels. The glycemic means were reduced during and after pregnancy compared to after pregnancy. The triglyceride concentrations were increased before and during pregnancy in relation to after pregnancy. The total cholesterol levels presented no changes.CONCLUSION: The use of experimental animals is suitable for evaluation of metabolic changes because the profile of answers found in this study was similar to human profile, showing the relevance of translational research to better understand the pathophysiological mechanisms and possible treatment for diseases.
الموضوعات
Animals , Female , Pregnancy , Models, Animal , Pregnancy, Animal/physiology , Rats, Wistar/physiology , Body Weight , Blood Glucose/analysis , Cholesterol/blood , Drinking , Glucose Tolerance Test , Insulin/blood , Litter Size , Reference Values , Time Factors , Triglycerides/bloodالملخص
Aim of the Study: This study investigates the effects of Capsicum frutescens supplemented diet (C.F.S.D) on fasting blood glucose level, biochemical parameters and body weight in alloxan induced diabetic Wistar rats. Experimental Design: 130 – 150g healthy forty male Wistar rats were divided into four groups as following; Group 1 served as a normal control and received normal feed-. Group 2 (Diabetic control) received normal feed-. Group 3 (Diabetic test 1) received normal feed + 1g Capsicum frutescens.-. Group 4 (Diabetic test 2) received normal feed + 2g Capsicum frutescens. Place and Duration of Study: This study was carried out in the department of Physiology, Faculty of Basic Medical Sciences, Delta State University, Abraka and the feeding lasted for three weeks. At the end of the experiments, the animals were sacrificed, blood samples were collected and then the serum was further subjected to biochemical analysis using biochemical analyzer (Reflotron Plus). Results: AST, ALT, ALP, GGT, Creatinine, Uric acid, total cholesterol and fasting blood sugar level in serum were increased however the high density lipoprotein cholesterol (HDL-c) of serum was decreased in diabetic control (group 2), compared with non-diabetic control (group 1). The administered Capsicum frutescens in the diet at 1g and 2g doses significantly reduced the fasting blood glucose level as well as the serum level of AST, ALT, ALP, GGT, Creatinine, Uric acid, total cholesterol, compared with diabetic control. Serum HDL was also significantly increased when compared with diabetic control P<0.05. Decrease in body weight in diabetic control group and increased in body weight of 1gand 2g Capsicum frutescens supplemented diet groups were also observed. Conclusion: The observed improvement in the biochemical parameters, blood glucose levels and body weight of alloxan induced diabetic Wistar rats by 1g and 2g Capsicum frutescens supplemented diet suggests Capsicum frutescens to possess, cardioprotective and anti-diabetic properties. Recommendation: The incorporation of Capsicum frutescens as spice in the diet of individuals who are diabetic, hypertensive and obese, is worthy of recommendation.
الموضوعات
Alloxan/adverse effects , Animals , Body Weight/metabolism , Capsicum , Glucose/metabolism , Fasting/blood , Food, Fortified , Diabetes Mellitus, Experimental/chemically induced , Liver/enzymology , Rats, Wistar/metabolism , Rats, Wistar/physiology , Thermogenesisالملخص
Food restriction reduces body weight and influence bone mass and also is correlated with bone mineraldensity (BMD). Mechanisms have been proposed for the loss of BMD after body weight reduction, includingreduced energy intake. Growing 8 wk-old Wistar male rats were randomly divided into Control and Calorierestriction associated with sucrose 30% (CRS). These animals were subjected to intermittent food restrictionduring 8 weeks and had free access to tap water and sucrose30% in distilled water. The rats were euthanizedat the end of week 8, blood collected from abdominal aorta artery, femurs cleaned of adherent soft tissues,scanned using dual energy X-ray absorptiometry, structural and material properties determined by three-pointbending testing in the mid-diaphyseal region, bone surface tested in a microhardness tester and microstructurewas assessed in a microcomputer tomography. In CRS animals body weight decreased significantly relative tothe Control animals. There was a clear option for high-sucrose beverage in CRS animals. No difference wasobserved in biochemical, densitometric and biomechanical analyzes. Results from micro CT showed onlysignificant difference in connectivity of trabecular bone. It has been suggested that rats submitted to foodrestriction consumed sugar not because of its inherent palatability, but in order to alter their macronutrientbalance and animals need to meet energy demands in high-sucrose.
الموضوعات
Animals , Rats , Biomechanical Phenomena/physiology , Caloric Restriction , Densitometry , Bone Density/physiology , Femur/physiology , Sucrose/administration & dosage , Dietary Supplements/adverse effects , Rats, Wistar/physiology , X-Ray Microtomographyالملخص
Cognitive dysfunction is reportedly associated with poorly-managed diabetes mellitus. In this study, we report the effect of oral treatment with combined leaf extract (CLE) of neem and bitter leaf on the prefrontal cortex of diabetic Wistar rats. Adult male Wistar rats were randomized to one of the following groups: control, diabetic (STZ-induced), STZ + CLE, STZ + metformin and CLE only. At euthanasia, paraffin sections of the prefrontal cortex were stained with cresyl fast violet; while malondialdehyde (MDA) and glutathione peroxidase (GPx) were assayed in prefrontal homogenates. Oral CLE produced normoglycemia in the treated hyperglycaemic rats. Besides, Nissl-stained prefrontal sections showed no morphologic deficits in all the groups except the untreated diabetic rats. In the latter, there was weak Nissl staining, while prefrontal MDA was significantly high at euthanasia, compared with the control and CLE-treated rats (P<0.05). This study showed that untreated diabetes mellitus is associated with prefrontal Nissl body deficit and oxidative stress in Wistar rats. The absence of these deficits in CLE-treated rats suggests a neuroprotective effect of the extract in streptozotocin-induced diabetic rats. This may improve the cognitive function of the prefrontal cortex in diabetes mellitus.
La disfunción cognitiva es presuntamente asociada con un mal manejo de la diabetes mellitus. En este estudio, se presenta el efecto del tratamiento oral combinado con extracto de hoja (CLE) de hoja de neem amarga sobre la corteza prefrontal de ratas Wistar con diabetes. Las ratas Wistar adultas fueron asignadas al azar a uno de los siguientes grupos: control, diabetes (STZ inducida), STZ + CLE, STZ + metformina y CLE. Después de la eutanasia, los cortes de parafina de la corteza prefrontal se tiñeron con violeta de cresil rápido, mientras que el malondialdehído (MDA) y la glutatión peroxidasa (GPx) fueron analizadas en homogenizados prefrontales. El CLE produce normoglucemia en las ratas hiperglucémicas tratadas. Además, las secciones prefrontales teñidas para Nissl no muestran ningún déficit morfológico en todos los grupos excepto en las ratas diabéticas sin tratamiento. En este último caso, hubo una tinción de Nissl débil, mientras que la MDA prefrontal fue significativamente más alta en comparación con los grupos de ratas control y las tratadas con CLE (p <0,05). Este estudio mostró que la diabetes mellitus no tratada se asocia con déficit prefrontal de cuerpos de Nissl y estrés oxidativo en ratas Wistar. La ausencia de estos déficits en las ratas tratadas CLE, sugiere un efecto neuroprotector del extracto en ratas diabéticas inducidas por estreptozotocina. Esto puede mejorar la función cognitiva de la corteza prefrontal en la diabetes mellitus.
الموضوعات
Rats , Azadirachta , Azadirachta/ultrastructure , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/therapy , Retrograde Degeneration , Streptozocin/adverse effects , Streptozocin/toxicity , Nigeria , Rats, Wistar/physiology , Rats, Wistar/bloodالملخص
El Síndrome Metabólico corresponde a una serie de trastornos relacionados con obesidad e inactividad física. Poco se conoce respecto de la falta de ejercicio, en estadios tempranos del desarrollo, en la susceptibilidad a un fenotipo insulinoresistente inducido por una dieta alta en grasas. Akt juega un rol clave en la síntesis de proteínas y el transporte de glucosa en el músculo esquelético y ha mostrado ser regulada por la actividad muscular. El objetivo del presente estudio fue determinar el efecto de la inactividad física temprana sobre el crecimiento muscular y la susceptibilidad de adquirir un fenotipo diabético y evaluar su relación con la expresión de Akt. Cuarenta ratas Wistar fueron distribuidas en 2 grupos (Grupos Control, Std) y Restricción de movimiento (RM). Entre los días postnatal 23 y 70 los animales del grupo RM fueron alojados en pequeñas jaulas que no permitían una actividad motora relevante. A partir del día postnatal 71 y hasta el día 102, 10 ratas de cada grupo fueron alimentadas con una Dieta Alta en Grasas (RM-DAG y Std-DAG). No se observaron diferencias en el peso corporal total pero DAG generó un significativo incremento en la grasa epididimal. RM generó una disminución significativa en el peso de los músculos sóleo. La captación de glucosa estimulada por insulina fue menor en el grupo RM-DAG. Los niveles de proteína Akt fueron menores en los grupos RM. El análisis de PCR a tiempo real mostró que la restricción de movimiento disminuyó los niveles de ARNm de AKT1 en el músculo sóleo, independiente de la dieta administrada. Estos hallazgos sugieren que la inactividad física temprana limita el crecimiento muscular y contribuye en la instauración un fenotipo insulino resistente, lo cual puede ser en parte explicado por una desregulación en la expresión de Akt.
Metabolic Syndrome is a group of conditions related to obesity and physical inactivity. Little is known about the role of physical inactivity, in early stages of development, in the susceptibility to insulin resistant phenotype induced by high fat diet. Akt plays a key role in protein synthesis and glucose transport in skeletal muscle and has been regulated by muscle activity. The objective of present study was to determine the effect of early physical inactivity on muscle growth and susceptibility to acquire a diabetic phenotype and to assess its relationship with Akt expression. Forty Wistar male rats were distributed in two groups (standard group, Std) and movement restriction (RM). Between days 23 and 70 after birth, RM group was kept in small cages that did not allow them to perform relevant motor activity. From day 71 to 102 after birth, 10 rats of each group were fed with hyperlipidic diet (groups Std-DAG and RM-DAG). No differences were observed in total body weight although DAG increased epididymal fat pad weight. RM decreased significantly the soleus weight. Insulin-mediated glucose uptake was lower in RM-DAG group. Akt protein levels were lower in RM groups. Real time RT-PCR analysis showed that movement restriction decreased mRNA levels of AKT1 in soleus muscle, regardless of supplied diet. These findings suggest that early physical inactivity limits muscle's growth and contributes to instauration of insulin resistant phenotype, which can be partly explained by dysregulation of Akt expression.
الموضوعات
Animals , Infant, Newborn , Rats , Exercise/physiology , Insulin Resistance/physiology , Insulin Resistance/genetics , Metabolic Syndrome/chemically induced , Proto-Oncogene Proteins c-akt/analysis , Proto-Oncogene Proteins c-akt/physiology , Proto-Oncogene Proteins c-akt/metabolism , Rats, Wistar/physiology , Rats, Wistar/metabolismالملخص
It is widely described in the literature that diabetic patients present hearing impairment. Despite the histological alterations of the internal ear structures in these patients as well as in experimental models of diabetes, to the best of our knowledge, an histological evaluation of the vestibulocochlear nerve have not been performed. In the present study, ultrastructural alterations are described and compared between a spinal nerves and a cranial nerve in rats with chronic induced diabetes. Male Wistar rats (n = 12), fed with standard diet from the animal care facility at 42 days of age were used. Induced diabetic animals (n=6) were fasted for 12 hours prior to being injected intraperitoneally with streptozotocin (STZ - 60mg/kg) in a single dose. Control animals (n=6) received (0.01 mol/l citrate buffer, pH 4.5) vehicle alone. Ten weeks after STZ injection the animals were perfused intracardially with Karnovsky solution. Right and left vestibulocochlear nerves were dissected and histologically processed for epoxy resin embedding. Samples were imaged with the transmission electron microscope. Large myelinated fibers with morphological signs of axonal atrophy in the vestibulocochlear nerves were readily observed. These results suggest that chronic STZ-induced diabetes in rats caused alterations in the myelinated fibers and Schwann cells, compatible to the classic diabetes signs and symptoms. Morphological alterations of the vestibulocochlear nerve in diabetes is described for the first time and contributes information for a better understanding of why there are changes in hearing observed in diabetic patients.
Se ha descrito ampliamente en la literatura que los pacientes diabéticos presentan discapacidad auditiva. En estos pacientes, a pesar de las alteraciones histológicas de las estructuras del oído interno, así como en modelos experimentales de diabetes, que mejoran nuestro conocimiento, la evaluación histológica del nervio vestibulococlear no ha sido realizada. Se describen y comparan las alteraciones ultraestructurales entre un nervio espinal y uno craneal en ratas con diabetes crónica inducida. Fueron utilizadas 12 ratas Wistar machos, de 42 días de edad, alimentadas con dieta estándar. Los animales diabéticos inducidos (n = 6) se mantuvieron en ayuno por 12 horas antes de ser inyectados por vía intraperitoneal con estreptozotocina (STZ - 60mg/kg) en una sola dosis. Los animales control (n = 6) sólo recibieron inyección de 0.01 mol/l buffer, citrato pH 4,5. Diez semanas después de la inyección de STZ, los animales fueron perfundidos intracardiacamente con solución de Karnovsky. Los nervios vestibulococlear derecho e izquierdo fueron disecados y procesados histológicamente para ser incluidos en resina epoxy. Las muestras fueron estudiadas con microscopio electrónico de transmisión. Fueron observadas fácilmente, grandes fibras mielinizadas con signos morfológicos de atrofia axonal en los nervios vestibulococlear. Estos resultados sugieren que la diabetes crónica inducida por STZ en ratas causó alteraciones en las fibras mielínicas y células del neurilema, compatible, con los signos y síntomas clásicos de la diabetes. Alteraciones morfológicas del nervio vestibulococlear en la diabetes son descritas por primera vez, lo que aporta información para una mejor comprensión de por qué hay cambios en la audición en los pacientes diabéticos.
الموضوعات
Animals , Male , Adult , Diabetes Mellitus, Experimental/chemically induced , Vestibulocochlear Nerve , Vestibulocochlear Nerve/ultrastructure , Microscopy, Electron/methods , Cochlear Nerve/physiopathology , Rats, Wistar/physiologyالملخص
The aim of the study was quantifying and morphologically analyzing the myenteric neurons of the small and large gastric curvatures of the glandular stomach of rats infected the tachyzoites of the Toxoplasma gondii for 30 days. Ten male rats were assigned into two groups: Control Group (CG) and Experimental Group (EG). The animals from the CG received saline solution orally whereas the EG animals received 104 tachyzoites of the T. gondii genotype III strain (BTU II). After 30 days, euthanasia was conducted for the removal of the stomach, which was dissected under the stereomicroscope for removal of the tunica mucosa and the tela submucosa. Whole mounts were stained with Giemsa. Quantification of the myenteric neurons was conducted by using a 40X-objective microscope in 40 microscopic fields for the region of the small gastric curvature and 40 fields for the large gastric curvature of the glandular stomach of the animals from both groups. The cell body of 50 myenteric neurons from each region was measured for each animal. Chronic experimental infection caused by the genotype III strain of Toxoplasma gondii was verified to reduce myenteric neuron density only in the small gastric curvature region of the glandular stomach, not resulting in significant changes in the size of the neurons.
Este estudio tuvo como objetivos cuantificar y analizar morfológicamente neuronas del plexo mientérico de las curvaturas gástricas menor y mayor del estómago glandular de ratones infectados durante 30 días por taquizoítos de Toxoplasma gondii. Fueron utilizados 10 ratas machos distribuidos aleatoriamente en dos grupos: grupo control (GC) y grupo experimental (GE). Los animales del GC recibieron solución salina por vía oral y los animales del GE recibieron, por la misma vía, 104 taquizoítos de Toxoplasma gondii de una cepa genotipo III (cepa BTU II). Tras 30 días, se realizó eutanasia para retirar el estómago, que fue disecado bajo el estereomicroscopio para retirar la túnica mucosa y tela submucosa. Preparados de membrana fueron coloreados por la técnica de Giemsa. La cuantificación de neuronas mientéricas se realizó con microscopía óptica, con objetivo de 40X en 40 campos microscópicos para la región de la curvatura gástrica menor y 40 campos para la curvatura gástrica mayor del estómago glandular, en ambos grupos. Se midió el área del cuerpo celular de 50 neuronas mientéricas de cada región en cada animal. Se verificó que la infección experimental crónica provocada por la cepa de genotipo III de Toxoplasma gondii en ratones, redujo la densidad de neuronas mientéricas solamente en la región de curvatura gástrica menor del estómago glandular, no llevando a alteraciones significativas el tamaño de las neuronas.
الموضوعات
Adult , Myenteric Plexus , Toxoplasmosis/physiopathology , Toxoplasmosis/chemically induced , Rats, Wistar/anatomy & histology , Rats, Wistar/physiologyالملخص
O objetivo deste estudo foi demonstrar os efeitos do tratamento tópico do creme à base de óleo de pequi (Caryocar coriaceum Wittm) utilizando 40 ratos (Rattus norvegicus albinus) da linhagem Wistar, machos, com 60 dias de idade. Esses foram divididos em dois grupos: I) composto por 20 ratos com feridas cutâneas tratados com aplicação tópica do creme base com 10% de óleo de pequi; II) com o mesmo número de animais que receberam a aplicação tópica do creme base sem o óleo de pequi. Após antissepsia e anestesia local foi produzida cirurgicamente ferida circular de 1 cm de diâmetro na região dorso lombar. As lesões cutâneas foram avaliadas sob o aspecto clínico, morfométrica e histológico no 3o, 7o, 14o e 21o dias pós-operatório. No grupo tratado com creme à base de óleo de pequi houve aceleração na evolução do processo cicatricial. As feridas dos animais desse grupo apresentaram redução significativa a partir do décimo quarto dia pós-operatório, bem como foram verificados nesse período achados histológicos característicos da etapa final do processo de cicatrização tais como: acentuada quantidade de fibroblastos, fibras colágenas e completo processo de reepitelização, enquanto que as feridas do grupo controle necessitaram de mais tempo para resolução do processo cicatricial.
The main objective of this study was to demonstrate the effects of topical treatment with ointment containing pequi oil (Caryocar coriaceum Wittm), using 40 male 60-day-old mice (Rattus norvegicus albinus) from the Wistar line. These were divided into two groups: I) composed by 20 mice with cutaneous wounds treated by topical application of the ointment based on 10% pequi oil; II) the same number of mice, receiving the topical application of ointment without pequi oil. After antisepsis and local anesthesia, round 1-cm-diameter wounds were made on the lower back region. The wounds were evaluated in regard to clinical, morphometric and histological aspects on the 3rd, 7th, 14th and 21st postoperative days. The group treated with the pequi ointment presented acceleration in the healing process. The animals' wounds of this group showed a meaningful reduction from the 14th postoperative day, when histological characteristics from the ending of the healing process were noted, such as a large amount of fibroblasts, collagen fibers and a complete process of reepithelialization, while the wounds of the control group needed more time for the healing process.
الموضوعات
Animals , Male , Rats , Wound Healing/drug effects , Plant Oils/therapeutic use , Malpighiales/chemistry , Rats, Wistar/physiologyالملخص
The morphological characteristics and haematological studies were studied in fifteen male albino rats (Wistar Strain) aged between 12 and 14 weeks and with a body weight of 150- 180g. The rats were allowed to feed on commercially prepared rat pellet and provided with fresh water ad libitum. The rats were divided into three groups; the rats were in groups A, B and C of 5 rats each. Group A served as control of the study; Group B was treated with Chloramphenicol at the dose rate of 25mg/kg body weight per os for 20 days; while Group C was treated for 25 days. Semen used in this study was obtained from the caudal epididymides while morphological aberrations were determined from spermatozoa counted after stained with Wells and Awa stain. Results of the spermiogram showed that the volume was decreasing as the prolonged dosage of chloramphenicol increases. The percentage motility in Group A (89.0 + 2.45 percent), differed significantly (p < 0.05) when compared to Group B (72.0 + 3.74 percent) and Group C (66.0 + 2.45 percent). The same pattern is observed in percentage liveability, morphological aberration and sperm concentration. This indicates that prolonged dosage of chloramphenicol will cause infertility in male animals. It is therefore concluded and recommended that prolonged dosage of chloramphenicol can cause infertility and or sterility. So it should not be used in male animals meant for mature breeding and artificial insemination programme.
Fueron estudiadas las características morfológicas y hematológicas de 15 ratas albinas Wistar, macho, entre 12 y 14 semanas y con un peso corporal de 150 - 180g. Las ratas fueron alimentadas con pellet preparado comercialmente y con agua fresca ad libitum. Las ratas fueron divididas en tres grupos de 5 ejemplares cada uno. El Grupo A sirvió como control; Grupo B fue tratado con cloranfenicol en dosis de 25mg/kg de peso corporal durante 20 días, mientras que el Grupo C recibió este tratamiento durante 25 días. El esperma utilizado en este estudio se obtuvo desde la cauda del epidídimo, donde las aberraciones morfológicas fueron determinadas a partir del conteo de espermatozoides, después de ser teñidos con la tinción de Wells y Awa. Los resultados del espermiograma puso de manifiesto que el volumen fue disminuyendo a medida que la dosis de cloranfenicol aumentaba. El porcentaje de motilidad en el grupo A (89,0 +/- 2,45 por ciento), fue diferente significativamente (p <0,05) en comparación con el Grupo B (72,0 +/- 3,74 por ciento) y Grupo C (66,0 +/- 2,45 por ciento). El mismo patrón se observó en los porcentaje de habitabilidad, aberración morfológica y la concentración de espermatozoides. Esto indica que la prolongación de la dosis de cloranfenicol puede causar infertilidad en los animales machos. Por lo tanto, se concluye y recomienda que una prolongada dosis de cloranfenicol puede causar infertilidad o esterilidad, así que no debe utilizarse en animales machos destinados a la cría y en los programas de inseminación artificial.
الموضوعات
Animals , Chloramphenicol/adverse effects , Infertility, Male/chemically induced , Infertility, Male/veterinary , Rats, Wistar/physiology , Rats, Wistar/bloodالملخص
OBJETIVO: O objetivo deste trabalho foi avaliar a influência das frações de parede celular de levedura (Saccharomyces cerevisiae) sobre alguns parâmetros nutricionais de ratos Wistar em crescimento. MÉTODOS: A biomassa de levedura (Saccharomyces cerevisiae), coletada sem sofrer o processo de termólise, foi recebida da usina São José, Zillo Lorenzetti (Macatuba, SP), em suspensão de, aproximadamente, (20 por cento p/v) de células. O fracionamento da parede celular da levedura foi realizado por extração diferencial, centrifugação e secagem em spray dryer. A importância como fibra da dieta foi determinada em ratos da linhagem Wistar, recém desmamados, por meio das seguintes avaliações: ganho de peso corporal, consumo de dieta (28 dias), quociente de eficiência da dieta, digestibilidade aparente da proteína, quantidade total de fezes, lipídeos e colesterol excretados nas fezes. RESULTADOS: Os animais que receberam a dieta contendo a fração glicana mais manana ganharam menos peso em relação aos demais tratamentos. A dieta com a fração manana foi a que proporcionou maior ganho de peso, seguida pela dieta padrão (AIN-P) e a dieta com 10 por cento de glicana insolúvel. Quanto ao quociente de eficiência da dieta, observou-se, ao longo dos 28 dias, que a dieta com a fração glicana mais manana foi a que apresentou os menores valores. As maiores porcentagens de digestibilidade aparente da proteína foram observadas nas dietas: padrão modificada (AIN-M), padrão (AIN-P) e (M) com 10 por cento da fração manana. As quantidades de lipídeos totais e colesterol excretados nas fezes variaram bastante entre as dietas, sendo que a dieta formulada com 10 por cento de fração manana foi a que promoveu maior excreção do colesterol. CONCLUSÃO: Ao final de 28 dias, os animais que receberam a dieta contendo 10,0 por cento da fração glicana mais manana apresentaram o menor consumo de dieta e ganharam menos peso em relação às demais dietas. A digestibilidade aparente...
OBJECTIVE: The objective of the present work was to assess the nutritional impact of Saccharomyces cerevisiae cell wall fractions on some nutritional parameters in growing Wistar rats. METHODS: Yeast (Saccharomyces cerevisiae) biomass collected without undergoing thermolysis came from the mill São José, Zillo Lorenzetti (Macatuba, SP) in a suspension of approximately 20 percent p/v of cells. Fractionation of the cell wall material was done by differential extraction, centrifugation, and drying in "spray dryer". The importance of the yeast cell components as dietary fibers was assessed in recently weaned Wistar rats by measuring weight gain, diet consumption (28 days), diet efficiency ratio, apparent protein digestibility, total amount of feces and lipids and cholesterol excreted in feces. RESULTS: Rats which were submitted to diets containing glycan plus mannan gained less weight when compared with the other diets. The mannan-containing diet yielded the highest weight gain, followed by the standard AIN diet (S-AIN) and the insoluble glycan diet. Regarding diet efficiency ratio, the diet containing glycan plus mannan produced the lowest values throughout the 28 days. The highest apparent protein digestibility was obtained for the modified standard diet, for the standard AIN diet, as well as for the 10 percent mannan-containing diet (M). Total lipids and cholesterol excreted in the feces varied substantially among the diets. The diet containing 10 percent mannan was the one that promoted the greatest excretion of cholesterol. CONCLUSION: At the end of 28 days, the rats submitted to the glycan plus mannan-containing diets consumed less food and gained less body weight than those submitted to the other diets. Apparent digestibility of all diets was high, 98.6 percent on average. The amounts of total lipids and cholesterol excreted in the feces varied considerably; however, the mannan-containing diet promoted proportionally more cholesterol...
الموضوعات
Animals , Rats , Mannans/adverse effects , Cell Wall/physiology , Polysaccharides/physiology , Rats, Wistar/physiology , Saccharomyces cerevisiae/physiologyالملخص
A cessação do treinamento físico (destreinamento) resulta em rápido acréscimo da massa adiposa, ganho depeso e resistência à insulina tanto em humanos quanto em animais. No entanto, os mecanismos moleculares envolvidos nesse processo permanecem desconhecidos. Diferentes proteínas intracelulares podem estar envolvidas no processo de aquisição de ganho de peso e diminuição na ação da insulina nesse modelo animal. Este estudo teve como objetivo investigar as vias PI 3-quinase/Akt e CAP/Cbl, ambas importantes na captação ou utilização de glicose estimulada por insulina no tecido muscular adiposo branco. Utilizou-se, ratos Wistar que foram submetidos a um protocolo de exercício de natação por 8 semanas. Posteriormente os animais foram destreinados e nesse mesmo período de cessamento do programa de exercício foi oferecida aos ratos uma dieta rica em lipídes. Para análise das proteínas de interesse, foi realizado o método de imunoblot e imunoprecipitação. Verifica-se, através dos resultados obtidos, que animais destreinados tem um ganho de peso e de gordura epididimal mais acentuado comparado a animais sedentários. Esse fato foi associado a uma maior responsividade à insulina no tecido adiposo através da via IRS/PI 3-quinase/Aktdos animais destreinados submetidos à dieta rica em lipídes. Além disso, verifica-se, que a via CAP/Cbl encontra-semais responsiva à insulina no tecido adiposo de animais destreinados em relação aos outros grupos experimentais. Conclui-se, que o destreinamento físico é acompanhado por um rápido período de ganho de peso e de massa adiposa e essas adaptações deve-se no mínimo em parte pela maior responsividade à insulina da via CAP/Cbl em tecido adiposo branco.
The termination of exercise training (detraining) results in rapid fat accretion, weight gain and insulin resistance in both humans and rats. There is evident relationship between physical inactivity and insulin resistance. Different mechanisms may be involved in insulin resistance in this animal model. The aim of this study was to investigate the PI3-kinase/Akt and CAP/Cbl signaling pathways both involved with insulin-stimulated glucose uptake in white adipose tissue in detrained and sedentary animals submitted a high-fat diet. Wistar rats were submitted to swimming training during 8 weeks. Next this period the animals stop the training and received a rich-fat diet. The proteins from the insulin signaling pathway were analyzed by immunoprecipitation and immunoblotting. The results demonstrated that detraining result in an increased body mass and rapid body fat accretion. This fact was associated with increases insulin responsiveness in adipose tissue through IRS/PI3-Kinase/Akt pathway in detrained rats fed with a rich-fat diet. In addition, the CAP/Cbl pathway in adipose tissue was more insulin responsives in the detrained animals feeding with a rich-fat diet than S-DHL animals. In conclusion, the cessation of exercise is accompanied by increased body mass and rapid fat accretion and this aspect to have relation at least in part to increased insulin responsiveness in adipose tissue through CAP/Cbl pathway.
الموضوعات
Animals , Male , Rats , Food Additives , Insulin Resistance , Obesity/physiopathology , Physical Conditioning, Animal , Rats, Wistar/physiology , Rats, Wistar/metabolismالملخص
OBJETIVO: Investigar se a suplementação com doses suprafisiológicas de beta-caroteno exerce efeito positivo no controle da hipertensão arterial, e detectar possíveis efeitos adversos dessa suplementação. MÉTODOS: Ratos espontaneamente hipertensos (n=12) e normotensos (n=12) com 20 semanas, foram submetidos a um período basal de 10 dias, e subdivididos em 4 grupos de 6 animais, suplementados com beta-caroteno em três diferentes doses: 2,5mg, 3,75mg e 5,0mg por animal, via gavagem orogástrica diária, durante 14 dias para cada dose, intercaladas por um período de wash-out de 7 dias; os grupos controle receberam apenas o veículo (óleo de coco). Foram ainda submetidos à avaliação ectoscópica para possível detecção de efeitos tóxicos ou interação entre nutrientes, e à análise dos parâmetros biológicos; a pressão sistólica foi aferida por pletismografia duas vezes na semana, em dias alternados. Após o período de suplementação os animais foram sacrificados, e tiveram o peso do fígado determinado pelo método de Scherle. RESULTADOS: A administração de beta-caroteno não levou a alterações dos parâmetros biológicos dos animais, assim como não foi detectado efeito tóxico. Quanto à pressão arterial sistólica, as duas linhagens apresentaram redução significante (p<0,05), sendo a maior redução observada durante administração da terceira dose. O peso médio do fígado foi de 7,25 (desvio-padrão 3,2) gramas, e a relação média do peso do órgão/média do peso corpóreo igual a 0,0192 para o grupo dos hipertensos. CONCLUSÃO: A suplementação de beta-caroteno tem efeito positivo tanto no controle quanto na prevenção da hipertensão arterial de ratos. A relação peso do fígado/peso corpóreo apresentou-se dentro dos padrões de normalidade.
OBJECTIVE: To investigate if supplementation with supraphysiological doses of beta-carotene has a positive effect on controlling hypertension and detect possible adverse effects of this supplementation. METHODS: 20-week-old spontaneously hypertensive rats (n=12) and normotensive rats (n=12) were submitted to a basal period of 10 days, then divided into 4 groups of 6 animals and supplemented daily by orogastric gavage with beta-carotene in 3 different doses: 2.5mg, 3.75mg and 5.0mg/animal during 14 days for each dose that was inserted by a seven day wash-out period; control groups received only coconut oil. Animals were submitted to ectoscopic evaluation to detect possible toxic effects or interaction between nutrients and analysis of biological parameters; systolic blood pressure was measured by plethysmography twice a week on alternate days; after the supplementation period, animals were killed and their livers weighed by the Scherle method. RESULTS: Administration of beta-carotene did not alter the animals' biological parameters or cause any toxic effects. Regarding systolic blood pressure, both lineages showed significant results (p<0.05), with the highest dose presenting the best results. The average liver weight was 7.25 (3.2 standard-deviation) grams, and the relationship between the average liver weight and body weight was 0.0192 for the hypertensive group. CONCLUSION: Beta-carotene supplementation was effective in controlling and preventing hypertension in rats. The relationship between liver weight and body weight was normal.
الموضوعات
Animals , Male , Rats , Hypertension/drug therapy , Rats, Wistar/physiology , Dietary Supplements/adverse effects , beta Carotene/therapeutic useالملخص
El objetivo del trabajo fue verificar, durante un período experimental de 210 días, los posibles efectos del etanol sobre la morfología y densidad de las neuronas mientéricas NADH-diaforasa, en el yeyuno de ratas alcohólicas. Utilizamos 10 animales (Rattus norvegicus) separadas en dos grupos: el control (n=5) que recibió una dieta proteica normal (22 por ciento) y agua ad libitum; el otro, alcohólico, que recibió dieta proteica normal NUVILAB (22 por ciento) y brandy de azúcar de caña diluido a 30 Gay Lussac (30 v/v). El segmento de yeyuno fue obtenido y sometido a técnicas histoquímicas para teñir las células nerviosas. La observación a través de microscopía de luz mostró que no hubo diferencias morfológicas de importancia entre las neuronas del grupo control y el sometido a alcoholismo. El recuento neuronal en el grupo control, llevado a cabo en 40 campos microscópicos (8,96 µm2), de las regiones mesentérica y antimesentérica, determinó 1.131 y 693 neuronas, respectivamente, mientras que en el grupo alcohólico se encontraron 1.229 y 860 neuronas, respectivamente. El incremento significativo en el número de neuronas en la región mesentérica, en el grupo de las ratas alcohólicas, es debido a un crecimiento físico menor de esos animales comparados con el grupo control. El etanol causó malnutrición y consecuentemente, las ratas alcohólicas mostraron una densidad neuronal más amplia debido a una dispersión menor.
The objective of our work was to verify, during an experimental period of 210 days, the possible effects of the ethanol on the morphology and density of the NADH-diaforase myenteric neurons in the jejunum of alcoholic rats. We used 10 animals (Rattus norvegicus) separated in 2 groups: the controls (n=5), that received a normal proteic diet (22%) and water ad libitum; the alcoholic, that received NUVILAB normal proteic chow (22%) and sugar cane brandy diluted at 30 Gay Lussac (30 v/v). The jejunum segment was collected and submitted to the histochemical technique to stain the nervous cells and, then, to the elaboration of membrane whole mounts. The observation through light microscopy showed that there are no expressive morphologic differences between the ganglia of neurons of the control and alcoholic rats. The counting of neurons, carried out in 40 microscopic fields (8.96µm2) in the control group, at the mesenteric and antimesenteric regions, found 1,131 and 693 neurons respectively, while, the alcoholic group found 1,229 and 860 neurons. The significant increase in the number of neurons in the mesenteric region, in the alcoholic rats, is due to the smaller physical growth of those animals when compared to the controls. The ethanol caused malnutrition and consequently the alcoholic rats showed a larger neuronal density due to its smaller dispersion.
الموضوعات
Animals , Infant , Rats , Neurons , Neurons/physiology , Myenteric Plexus/anatomy & histology , Myenteric Plexus , Myenteric Plexus/physiology , Alcoholism/complications , Alcoholism/physiopathology , Alcoholism/metabolism , Rats, Wistar/anatomy & histology , Rats, Wistar/physiology , Jejunum , Jejunum/physiologyالملخص
Estudo das modulações do ritmo teta a da dessincronização no córtex cerebral do rato durante comportamento atento [tese]. São Paulo: Faculdade de Medicina, Universidade de São Paulo; 2004. Os eletroscilogramas de elétrodos corticais montados em matriz (20 elétrodos) foram registrados para se estabelecer um mapa da superfície do córtex cerebral durante vigília atenta e no sono dessincronizado. No córtex frontal a dessincronização foi predominante, enquanto em todas as outras áreas o ritmo teta prevalece, com frequência e voltagem relacionadas a intensidade e tipo de comportamento. A dessincronização e o ritmo teta são especificamente relacionados com o padrão de comportamento e são sinais de comando de grupos neuronais que mobilizam padrões funcionais que geram a organização de cada comportamento. Conclui-se que o ritmo teta e a dessincronização estão relacionados a focalização da atenção, representando a atividade de grupos neuronais relacionados com o conteúdo da vigília atenta e do comportamento onírico / Theta rhythm modulations and of the desynchronization in the cerebral cortex of the rat during attentive behavior [thesis]. São Paulo: Faculdade de Medicina, Universidade de São Paulo; 2004. The electro-oscillograms of cortical electrodes arranged as matrices (20 electrodes) were recorded to establish a map of the cortex in wakefulness and in desynchronized sleep. In the frontal cortex desynchronization was predominant, whereas in all other areas theta waves prevailed, with frequency and extent of the theta related with the intensity and the behavior type. It was concluded that desynchronization and theta rhythm are specifically related the patterns and commanding specific neuronal population, mobilizing to the functional patterns organization generator of each behavior. Then, the theta rhythm it is related to attention focalization, representing the activity of neuronal population specifically related to wakefulness or oniric experience contents. The idea that theta waves and desynchronization composition are command signals that mobilize sets of circuits as a multiplexing mechanism are discussed...