title: Hypotensive effect of SA446, an angiotensin converting enzyme inhibitor, in 2-kidney, 1-clip renal hypertensive and normotensive dogs.
abstract: Hypotensive effects of SA446, an angiotensin converting enzyme (ACE) inhibitor, and effects on the renin-angiotensin system were evaluated in conscious normotensive and 2-kidney, 1-clip renal hypertensive dogs. SA446 (1 mg/kg, p.o.) remarkably inhibited the pressor response to angiotensin (Ang) I between 1 and 6 hr after the administration in normotensive dogs. SA446 significantly decreased blood pressure at 10 mg/kg, p.o., in normotensive dogs. During repeated administration of SA446 (100 mg/kg/day, p.o.) for 13 weeks, the blood pressure was lowered, and the pressor response to Ang I and plasma ACE activity were strongly inhibited. ACE activities in the aorta and kidney were also inhibited. Plasma renin activity and plasma Ang I concentration increased by repeated SA446 application, while plasma aldosterone concentration decreased. The hypotensive effect of SA446 (5 mg/kg, p.o.) was more potent in 2-kidney, 1-clip renal hypertensive dogs than in normotensive dogs. SA446 had longer inhibitory effects on the pressor response to Ang I and more potent hypotensive effects than captopril. The hypotension caused by SA446 appears to be associated mainly with an inhibition of ACE in plasma and also in the vascular wall.
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D000803:Angiotensin I / Q000037:antagonists & inhibitors / Q000097:blood; D000806:Angiotensin-Converting Enzyme Inhibitors; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002216:Captopril / Q000494:pharmacology; D004285:Dogs; D005260:Female; D006977:Hypertension, Renal / Q000188:drug therapy*; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000097:blood; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System / Q000187:drug effects*; D013438:Sulfhydryl Compounds; D053778:Thiazolidines
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D013438:Sulfhydryl Compounds; D053778:Thiazolidines; D000803:Angiotensin I; D002216:Captopril; D015097:3-Mercaptopropionic Acid; C033437:rentiapril; D007703:Peptidyl-Dipeptidase A; D012083:Renin