[Adrenal cortex and avitaminosis A: II. Complementary in vivo and in vitro studies on inhibition of corticoidogenesis in moderate deficiency in the rat. III. In vivo criterion for activity: glycemic response to ACTH].

II. We set up new experiments, both in vivo and in vitro, in order to explain the impaired adrenal response to stress, of vitamin A middly deficient, male Wistar rats. Injections of progesterone, 6 mg s.c. or i.p. every other day, did not improve the deficiency curse in our rats. In agreement with these results, we have found that, in vitro, the delta5-3beta hydroxysteroide dehydrogenase is not altered in deficient glands; we confirmed it histochemically. On the other hand, the 11beta and 18 hydroxylase activities are lowered in vitro (and presumably in vivo). When conditions of hyperactivity are established, the conversion of deoxycorticosterone (DOC) to 18 OH-DOC or to corticosterone is reduced and DOC accumulates in the incubation medium. III. When middly deficient intact rats are injected with ACTH i.p. (2UI p. 100 g of body weight), only some of them are found to have normoglycemia or hyperglycemia, 45 or 60 minutes after injection, as the controls do. Many deficient rats become hypoglycemic as the adrenalectomised animals do. We think that the changes in the glycemia after ACTH injection could be used to discriminate between the more or less deficient rats.