EFFECT OF DIBUTYRYL-CYCLIC-AMP ON PLASMA-RENIN ACTIVITY IN NORMAL MENAND PATIENTS WITH PRIMARY ALDOSTERONISM

Dibutyryl cyclic AMP (DBcAMP) directly stimulates the release of renin from the juxtaglomerular (JG) cells in vitro. We investigated the eff ect of DBcAMP on plasma renin activity (PRA) in 6 normal men and in 8 patients with primary aldosteronism (PA). A 20-min infusion of 0.33 mg /kg/min of DBcAMP significantly increased PRA in normal men, but had l ittle effect on PRA in patients with PA, Infusion of DBcAMP significan tly reduced the blood pressure and the levels of serum sodium and pota ssium in normal men and the patients with PA, Infusion of DBcAMP signi ficantly increased urine volume in normal men, but not in patients wit h PA, Urinary excretion of sodium increased in both groups after the i nfusion of DBcAMP, Thus, DBcAMP did not stimulate renin release in pat ients with PA, suggesting that the chronic excess production of aldost erone suppresses the release of renin from JG cells. (C) 1997, Editric e Kurtis.