Further studies on the inhibitory effects of somatostatin on the growth and steroidogenic capacity of rat adrenal zona glomerulosa.

Chronic somatostatin administration was found to partially reverse the ACTH-enhanced growth of the rat zona glomerulosa. The effect of somatostatin was completely superposable to that of captopril, a specific inhibitor of the angiotensin-converting enzyme, and the inhibitory actions of these two agents did not cumulate. Neither somatostatin nor captopril counteracted the ACTH-induced stimulation of the growth and steroidogenic capacity of the rat zona fasciculata. These findings support the view that somatostatin acts as an exclusive and specific modulator of the adrenoglomerulotrophic action of the renin-angiotensin system.