[Effect of mineralocorticoids on the Na, K-ATPase activity of the rat brain].

The effect of desoxycorticosterone (DOC) on Na, K-ATPase activity was studied in vivo and in vitro on microsomal rat brain fractions. An hour after intramuscular administration of DOC a noticeable increase in the enzyme activity was observed. Preincubation of microsomal brain fractions with 5 and 15 mkg/ml of DOC caused a decrease in Na, K-ATPase activity, with the results evident 3-5 minutes after the addition of the hormone into the incubation medium. The idea of a two-phase hormonal effect is suggested. It is likely that desoxycorticosterone effect is realized both by the direct influence, on Na, K-ATPase of the brain plasma membrane and by the influence on the biosynthesis.