[Hydrocortisone modification during intrauterine development of the activity of brain tyrosine hydroxylase in adult white rats].

The activity of the key enzyme of catecholamine synthesis, tyrosine hydroxylase (TH), and the level of corticosteroids in blood were estimated in adult white rats in the normal state and after stress after their mothers were treated with hydrocortisone during pregnancy. The disturbance of the balance of corticosteroids during intrauterine development decreases the initial activity of TH in hypothalamus but increases it in the cortex of adult animals. Besides, after stress the increase in the level of corticosteroids in blood is less pronounced but the TH activation in hypothalamus is more distinct. Hence, the increase in the level of corticosteroids during intrauterine development induces long-term changes in the TH activity in brain which may be one of the causes of decrease in reactivity of adult animals after stress.