[Analysis of an increase in the body's sensitivity to insulin].

In adult albino rats, increased sentivity of the organism to insulin action caused by systematic muscular exercises preserved in conditions of adrenergic blockade but was reduced by theophylline administration (inhibition of 3'-5'-AMP-phosphodiesterase activity). The sensitivity to insulin action 3'-5'-phosphodiesterase (in muscles, liver, and adipose tissue) increased during adaptation to muscular activity. Simultaneously the insulin inactivation in muscle and liver tissues also increased.