Revista Brasileira de Medicina do Esporte
Print version ISSN 1517-8692
NUNES, Wilton Marlindo Santana and MELLO, Maria Alice Rostom de. Glicidic metabolism in rats submitted to denervation of skeletal muscle and swimming exercise. Rev Bras Med Esporte [online]. 2009, vol.15, n.1, pp. 42-45. ISSN 1517-8692. http://dx.doi.org/10.1590/S1517-86922009000100009.
Denervation of the skeletal muscle involves well known alterations of the glucose metabolism; however, little is known about the influence of these alterations on the peripheral sensitivity to insulin of the animal as a whole. This study aimed to analyze the glucose metabolism in the soleus muscle of rats submitted to denervation as well as their response to exogenous insulin and to exercise. Wistar rats aged from 3 to 5 months were submitted to section of the sciatic nerve in the right paw. After 48 hours, half of them started a swimming program of 1 hour/day, 5 days/week. Intact animals, either submitted to exercise or not, were used as control. The rats were submitted to the insulin tolerance test after 28 days for evaluating the response to insulin. The results were analyzed by determination of the blood glucose removal rate (Kitt). In another batch of animals, slices of the denerved soleus muscle and the counterlateral intact paw were incubated in the presence of glucose (5.5mM), containing [3H]2-deoxyglucose (0.5µCi/mL) and [U14C] glucose (0.25µCi/mL) and insulin (100U/mL), for analysis of glucose uptake, oxidation and glycogen synthesis. Denerved rats submitted to exercise presented KiTT (%/min) higher (7.22 ± 0.49) than the sedentary animals (5.31 ± 0.22), and the sedentary control animals (4.53 ± 0.27). Glucose uptake (3.55 ± 0.21 µmol/g.h) by the denerved muscle was lower than those of the opposite muscle in the sedentary rats (5.12 ± 0.38 µmol/g.h). Chronic exercise raised glucose uptake and oxidation in the counterlateral muscle (uptake: 6.53 ± 0.37, oxidation: 20.39 ± 1.91) and in the denerved muscle (uptake: 5.70 ± 0.41, oxidation: 20.54 ± 1.97). The same situation occurred with the exercised control group. These results suggest that restricted alterations of the muscular glucose metabolism influenced the response to insulin of the animals as a whole. Furthermore, exercise improved the uptake and use of glucose in the denerved muscle.
Keywords : training; glucose transport; immobilization.