Blood pressure responses to enalapril in rats with one- and two-kidney DOC-NaCl hypertension.

Blood pressure responses to the angiotensin-converting enzyme (ACE) inhibitor enalapril were investigated in rats with salt-dependent hypertension. In both one- and two-kidney deoxycorticosterone (DOC)-NaCl hypertension, enalapril (50 mg/kg p.o.) caused a similar, slight blood pressure fall, which passed off with continuation of the treatment. Changes in the salt concentration of the drinking fluid (from 1% NaCl to 0.2% NaCl in the one-kidney rats and from 1% NaCl to 2% NaCl in those with intact kidneys) did not alter the depressor effect of enalapril. Plasma renin activity in all DOC-NaCl hypertensive groups was negligible. Our results indicate that in DOC-NaCl hypertensive rats, the presence of intact kidneys vs. one kidney has no influence on the blood pressure response to ACE inhibition. The blood pressure-lowering effect of enalapril may result from local converting enzyme inhibition in tissues.