[Changes in cyclic nucleotide metabolism in compensatory adrenal hypertrophy (following unilateral adrenalectomy)]

The cyclic nucleotide content, adrenocortical adenylatecyclase, guanylatecyclase, cAMP and cGMP phosphodiesterase activity, as well as the blood corticosteroid content of guinea pigs were determined at the different periods after bilateral adrenalectomy. The raised basal adenylatecyclase effect was also seen during compensatory hypertrophy of the sole adrenal. The response of adenylatecyclase to ACTH and Na is also enhanced at this moment. It is suggested that a physiological increase in the blood ACTH concentration, resultant of unilateral adrenalectomy, intensifies the adenylatecyclase catalytic activity and does not induce enzyme desensitization. The guanylatecyclase activity grows. It was established that changes in both cyclase activities are dependent on the postoperative time and are equal by character. The alteration of adenylatecyclase state always leads to the rise of guanylatecyclase activity. Changes in the cAMP and cGMP phosphodiesterase activity were not observed.