Metabolismo glicídico em ratos submetidos à imobilização por desnervação do músculo esquelético
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Data
2005-04-29
Autores
Nunes, Wilton Marlindo Santana [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Este estudo visou analisar o metabolismo da glicose no músculo sóleo de ratos submetidos a desnervação bem como a resposta do animal como um todo à insulina exógena e ao exercício. Os animais foram tratados de acordo com o Guide for care use of laboratory animals. (National Research Council, 1996). Para isso foram realizados 3 experimentos. No primeiro, ratos adultos (3 a 5 meses) foram submetidos à secção do nervo isquiático da pata direita. Observou-se redução da captação de glicose pelo músculo sóleo isolado da pata desnervada após 3 e 7 dias mas não após 28 dias em relação a animais controles íntegros. Não houve diferença após 3 e 7 dias na captação de glicose pelo músculo sóleo da pata contralateral em relação ao animal controle. Houve aumento da captação de glicose na pata contralateral 28 dias após a desnervação. Verificou-se que após 28 dias de desnervação, não houve reinervação do nervo isquiático. A taxa de remoção da glicose em resposta à insulina exógena após 28 dias de desnervação foi superior à de animais controle íntegros e aquela observada após 3 e 7 dias de desnervação. No segundo, ratos nas mesmas condições, após 48 h de desnervação iniciaram programa de natação 1h/dia, 5dias/semana, durante 28 dias. Ratos desnervados submetidos ao exercício mostraram maior taxa de remoção da glicose sangüínea em resposta à insulina exógena comparados aos sedentários e a animais controle íntegros. O exercício elevou a captação e a oxidação da glicose pelo músculo contralateral e pelo desnervado assim como pelo músculo de animais controles íntegros. Esses resultados sugerem que alterações restritas do metabolismo glicídico muscular influenciam a homeostase glicêmica do animal. Além disso, o exercício melhora o aporte e a utilização da glicose no músculo desnervado...
This study aimed to analyze the metabolism of glucose in the soleus muscle of rats submitted to denervation, as well as the response of the animal as a whole to exogenous insulin and to exercise. To do this, 3 experiments were carried out. In the first, adult rats (3 to 5 months old) were submitted to section of the sciatic nerve in the right paw. A reduction was observed in the uptake of glucose by the isolated soleum muscle of the denervated paw after 3 and 7 days, but not after 28 days in relation to the whole control animals. There was no difference after 3 and 7 days in glucose uptake by the soleum muscle of the opposite paw in relation to the control animal. There was increased glucose uptake in this same paw 28 days after denervation. The rate of glucose removal in response to exogenous insulin after 28 days of denervation was higher than that of whole control animals and those observed after 3 and 7 days of denervation. In the second experiment, rats in the same conditions, after 48 h of denervation started a swimming program 1h/day, 5day/week, for 28 days. The denerved rats submitted to exercise showed a higher blood glucose removal rate in response to exogenous insulin compared to the sedentary and whole control animals. Exercise raised the uptake and oxidation of glucose by the opposite muscle and by the denervated one, as well as by the muscles of the whole control animals. These results suggest that restricted alterations of the muscular glucose metabolism influenced the glycemic homeostasis of the animal. Furthermore, exercise improved the uptake and use of glucose in the denerved muscle. In the third experiment, adult rats in the same conditions as in the first study, had an assessment made of their insulin secretion by isolated pancreatic islets, incubated in the presence of growing concentrations of glucose (2.8; 5.6; 8.3 and 16.7 mM)... (Complete abstract, access undermentioned electronic address)
This study aimed to analyze the metabolism of glucose in the soleus muscle of rats submitted to denervation, as well as the response of the animal as a whole to exogenous insulin and to exercise. To do this, 3 experiments were carried out. In the first, adult rats (3 to 5 months old) were submitted to section of the sciatic nerve in the right paw. A reduction was observed in the uptake of glucose by the isolated soleum muscle of the denervated paw after 3 and 7 days, but not after 28 days in relation to the whole control animals. There was no difference after 3 and 7 days in glucose uptake by the soleum muscle of the opposite paw in relation to the control animal. There was increased glucose uptake in this same paw 28 days after denervation. The rate of glucose removal in response to exogenous insulin after 28 days of denervation was higher than that of whole control animals and those observed after 3 and 7 days of denervation. In the second experiment, rats in the same conditions, after 48 h of denervation started a swimming program 1h/day, 5day/week, for 28 days. The denerved rats submitted to exercise showed a higher blood glucose removal rate in response to exogenous insulin compared to the sedentary and whole control animals. Exercise raised the uptake and oxidation of glucose by the opposite muscle and by the denervated one, as well as by the muscles of the whole control animals. These results suggest that restricted alterations of the muscular glucose metabolism influenced the glycemic homeostasis of the animal. Furthermore, exercise improved the uptake and use of glucose in the denerved muscle. In the third experiment, adult rats in the same conditions as in the first study, had an assessment made of their insulin secretion by isolated pancreatic islets, incubated in the presence of growing concentrations of glucose (2.8; 5.6; 8.3 and 16.7 mM)... (Complete abstract, access undermentioned electronic address)
Descrição
Palavras-chave
Medicina esportiva, Desnervação, Metabolismo Glicídico, Músculo Esquelético, Denervation, Glycidic Metabolism, Skeletal Muscle
Como citar
NUNES, Wilton Marlindo Santana. Metabolismo glicídico em ratos submetidos à imobilização por desnervação do músculo esquelético. 2005. viii, 194 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2005.