[Glucose metabolism in epididymal adipocytes of rats taking voluntary exercise]

The purpose of this study was to investigate the effects of voluntary running on the glucose metabolism in isolated adipocytes. Male rats of the Wistar strain, 5 weeks old were separately fed on usual rat food in cages equipped with a rotating wheel. The control rats were kept in small cages without wheels for 8 weeks in both experiments. The exercised rats ran approximately 2 km/day during this period. There were significant differences in the body weights and the weights of the epididymal fat pads between the exercised rats (373.5 +/- 10.3 g SEM and 4.2 +/- 0.3 g SEM) and the sedentary rats (437.8 +/- 17.6 g SEM and 7.9 +/- 0.3 g SEM) (p less than 0.05 in both cases). The rate of [U-14C]-glucose oxidation measured by 14CO2 production in adipocyte cultures showed a tendency toward greater stimulation in the exercised rats than in the sedentary ones, both when no insulin was added to the incubating medium (0.42 +/- 0.18% SEM vs. 0.11 +/- 0.02% SEM, p less than 0.10) and when insulin was added (0.81 +/- 0.36% SEM vs. 0.15 +/- 0.02% SEM, p less than 0.05). Hexokinase activity in the cells also seemed to be more stimulated in the exercised rats than in the sedentary ones. Conversion of [U-14C]-glucose to triglyceride was not affected significantly in the above experiment either with respect of the exercised rats vs. sedentary rats or with respect of the presence of insulin in the incubating medium.(ABSTRACT TRUNCATED AT 250 WORDS)