[Age-dependent characteristics of the regulation of cytoplasmic NADP+-dehydrogenases in the liver of rats on different diets].

It is established that the activity of malate dehydrogenase and glucose-6-phosphate dehydrogenase in rats aged 1,3 and 12 months lowers under fasting and on high-fatty diet and in old animals (24 months) on a high-fatty diet only the glucose-6-phosphate dehydrogenase activity decreases. When rats after fasting are put on high-carbohydrate diet the activity value of the mentioned enzymes has already returned to the initial level after 12 hours in rats aged 1 and 12 months and in rats aged 3 months it exceeds that activity in intact rats. The rise in the activity of the determined enzymes is completely blocked by the preliminary administration of actinomycin D. The isocitrate dehydrogenase activity remains unchanged under conditions of maintaining animals on different diets.