Short-term treatment with captopril in hypertension due to acute glomerulonephritis

We report that the inhibition of the angiotensin converting enzyme is an effective short-term treatment of low-renin hypertension in acute glomerulonephritis (AGN). We treated 9 patients who had AGN with moderate to severe hypertension and suppressed plasma renin activity with 25-50 mg of captopril per os every 6-8 hours. Control of blood pressure was achieved in 1-2 hours and maintained thereafter. Captopril therapy was associated with an increase in plasma renin activity, a decrease in plasma aldosterone and an increase in the urinary excretion of prostaglandin E2 and kallikrein, independent of changes in urine output. Creatinine clearance increased 39.6 +/- SE 15.2% with captopril and decreased in the postcaptopril period, suggesting that captopril exerted a reversible effect on glomerular filtration rate, possibly modifying intrarenal vasoconstriction. Our study shows that rapid control of hypertension in AGN may be obtained with oral inhibition of the angiotension converting enzyme. Stimulation of PGE2 and kinins, as well as angiotensin II blockade appear to contribute to the hypotensive effect of the drug; by inference, the suppressed activity of vasodilator systems seems to play a significant role in the hypertension of AGN.