Pharmacological studies on (4S)-1-methyl-3-[(2S)-2-[N-((1S)-1-ethoxycarbonyl-3-phenylpropyl)amino] propionyl]-2-oxo-imidazolidine-4-carboxylic acid hydrochloride (TA-6366), a new ACE inhibitor: I. ACE inhibitory and anti-hypertensive activities.
TA-6366 and its active metabolite 6366A inhibited swine renal angiotensin converting enzyme (ACE) activity with IC50s of 9900 and 2.6 nM, respectively. TA-6366 (0.05-0.5 mg/kg, p.o.) inhibited the angiotensin I (AT-I)-induced pressor response in rats. 6366A augmented bradykinin (BK)-induced contraction of guinea pig ileum more potently than captopril. However, when the augmentation on BK-induced hypotension in rats was used as an indicator, TA-6366 was less active than captopril. TA-6366 increased plasma renin activity and plasma AT-I concentration. Oral administration of TA-6366 lowered the blood pressure in two-kidney one-clip renal hypertensive rats at 0.5 to 2 mg/kg and in spontaneously hypertensive rats (SHRs) at 2 to 10 mg/kg. The antihypertensive effect of TA-6366 was approximately 5 times more potent than that of captopril and almost as potent as that of enalapril. In SHRs, the antihypertensive action of TA-6366 was intensified in potency when administered repeatedly. The duration of action was longer than those of captopril and enalapril. However, TA-6366 had no substantial effect on the blood pressure in DOCA/saline hypertensive rats. These results indicate that TA-6366 is a potent and long lasting antihypertensive agent and that its antihypertensive action is attributable to the inhibition of ACE.
Kubo
M
M
Safety Research Laboratory, Tanabe Seiyaku Co., Ltd., Osaka, Japan.
Kato
J
J
Ochiai
T
T
Ishida
R
R
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D003900:Desoxycorticosterone; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology; D006978:Hypertension, Renovascular / Q000503:physiopathology; D007093:Imidazoles / Q000494:pharmacology*; D048289:Imidazolidines; D007672:Kidney Cortex / Q000187:drug effects / Q000201:enzymology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D012083:Renin / Q000097:blood; D013552:Swine
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D007093:Imidazoles; D048289:Imidazolidines; D003900:Desoxycorticosterone; C065166:imidapril; D012083:Renin