Renal effects of captopril in chronic heart failure

: The effect of captopril on renal function, central hemodynamics and the hormonal status was studied in 14 patients with chronic congestive heart failure in single administration of the drug at a dose of 25 mg and during short-term course therapy at a daily dose of 75 mg for 7 days. Captopril single administration was shown to cause an increase in natriuresis by 121% and diuresis by 120%. Correlation analysis showed that the natriuretic effect of captopril resulted from a decrease in tubular sodium reabsorption which, in its turn, was determined by a decrease in the production of angiotensin II and changes of pritubular circulation. Seven-day course therapy was accompanied by the patients' improved general status, improved indices of hemodynamics, and better tolerance to physical exercise. At the same time diuresis and renal excretion of sodium were above the basal level by 113 and 86%, respectively. It can be assumed that this natriuretic effect was determined by the suppression of angiotensin II, aldosterone and probably norepinephrine and vasopressin production. The analysis has shown that a favorable captopril renal effect is not mediated through improved central hemodynamics but results from changes of the hormonal and neurohumoral status.