[The acute effects of the new angiotensin I-converting enzyme inhibitor, enalapril maleate, on blood pressure, plasma renin, aldosterone and kinins in hypertensive patients].
The acute antihypertensive effect of a new long-acting oral angiotensin I-converting enzyme (ACE) inhibitor, enalapril maleate, was assessed in 20 hypertensive patients, of whom 14 had essential hypertension, 4 had renovascular hypertension, one had hypertension associated with chronic renal failure, and one had primary aldosteronism. Enalapril maleate significantly lowered the blood pressure in either low-renin or normal- and high-renin hypertensives. There was a significant correlation for all patients as a group between the pretreatment levels of serum ACE activity and the reduction in mean blood pressure (r = -0.454, p less than 0.05, n = 20) 2 h after drug administration. The serum ACE activity decreased maximally 3 to 4 hours after drug administration and did not return to baseline levels within 24 h. There was a significant correlation between the reduction in mean blood pressure and changes in ACE activity 90 min and 2 h after drug administration, respectively, for all patients as a group (r = 0.495, p less than 0.05, n = 20, at 90 min; r = 0.508, p less than 0.05, n = 20, at 2 h). The plasma renin activity (PRA) significantly increased in normal- and high-renin hypertensives but not in low-renin hypertensives. There was a close correlation between the reduction in mean blood pressure and the PRA 8 h after drug administration in normal- and high-renin patients (r = -0.623, p less than 0.05, n = 13), while no such relationship was observed in low-renin patients. The plasma aldosterone concentration (PAC) significantly decreased within 3 h, the lowest values occurring at 8 h after drug administration, and it returned to baseline levels within 24 h in all patients. No relationship was found between the reduction in mean blood pressure and changes in PAC after drug administration in either low-renin or normal- and high-renin hypertensives. The plasma bradykinin concentration (PBC) increased within 1 h, the highest values occurring at 3 h after drug administration, and returned to baseline levels within 24 h in low-renin hypertensives, while the PBC was significantly increased at 4 h and had not returned to baseline levels within 24 h in normal- and high-renin hypertensives. There was a significant correlation between percentage changes in mean blood pressure and those in PBC 90 min after drug administration in normal- and high-renin hypertensives (r = -0.556, p less than 0.05, n = 13), while no relationship was observed between them in low-renin hypertensives.(ABSTRACT TRUNCATED AT 400 WORDS)
Gotoh
M
M
Mizuno
K
K
Hashimoto
S
S
Kunii
N
N
Fukuchi
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000097:blood*; D000806:Angiotensin-Converting Enzyme Inhibitors; D001794:Blood Pressure / Q000187:drug effects*; D001920:Bradykinin / Q000097:blood; D004151:Dipeptides / Q000097:blood / Q000627:therapeutic use*; D004656:Enalapril; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D006978:Hypertension, Renovascular / Q000188:drug therapy; D007705:Kinins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012083:Renin / Q000097:blood*
D000806:Angiotensin-Converting Enzyme Inhibitors; D004151:Dipeptides; D007705:Kinins; D000450:Aldosterone; D004656:Enalapril; D012083:Renin; D001920:Bradykinin