To elucidate factors producing destructive changes in the adrenal cortex under severe stress, the following experiments were performed: 1) severe combined stress (KC) including unilateral adrenalectomy and fixation in supin position for 24 h (control group); 2)hypophysectomy KC; 3) thyroidectomy KC; 4) bilateral orchiectomy KC; 5) injection of vitamine "E" for 14 days + KC. The adrenals were studied by a complex of morphometrical and histochemical methods. Hypophysectomy prevented estructive changes in the adrenal cortex under KC. This effect was not connected with hypofunction of the thyroid gland and the testes, as their excision (in rats without hypophysectomy) did not prevent the development of necrobiotic changes in the adrenal cortex. A suggestion is made on a "corticolytic" effect of ACTH which reveals itself under severe stress. Destruction of adrenocorticocytes is supposed to result from activation of peroxide oxidation of lipids. This is indirectly supported by a large number of lipofuscin containing cells, by decrease in the activity of alkaline phosphatase and ATPh-ase, by activation of acid phosphatase and also by decreasing alterative phenomena at the injection of vitamine "E".