Effect of insulin on glucose metabolism in isolated adipocytes and in diaphragm: effect of age and neonatal nutrition.

Differences in the response of isolated adipocytes to insulin were found in relation to the age and early postnatal nutrition. In old rats (15 months) an impaired stimulation of 14C-glucose incorporation into lipids was found after insulin as compared to young animals (1 or 2 months old). In isolated fat cells from young neonatally underfed rats a higher increase of insulin induced lipogenesis was observed than in controls. The response to insulin, however, was not influenced by neonatal nutrition inold rats. Glucose oxidation in the diaphragm was also lower in older animals (4 months) than in young (1 month) rats. The stimulation of glucose oxidation by insulin was higher in neonatally underfed rats as compared to overfed ones during the suckling period. The rise of glucose oxidation after insulin decreased with age. These results showed that the response of muscular and adipose tissue decreases by age and that nutrition during the early postnatal period may affect the influence of insulin on the metabolsim of glucose in adipose and muscular tissue in young animals.