Antihypertensive action of a non-sulfhydryl angiotensin converting enzyme inhibitor (CV-3317) in various hypertensive models

The antihypertensive action of N-[N-[(S)-1-ethoxycarbonyl-3-phenyl-propyl]-L-alanyl]-N-(indan-2-yl) glycine hydrochloride (CV-3317), a nonsulfhydryl compound characterized as an angiotensin converting Enzyme inhibitor in our previous work, was examined in hypertensive animal models. In 2-kidney, 1 clip hypertensive rats and dogs, CV-3317 (3 and/or 10 mg/kg, p.o.) produced a sustained antihypertensive action of about 15 to 25 mmHg. Daily oral administrations of CV-3317 (1 to 10 mg/kg/day) to spontaneously hypertensive rats (SHR) for 5 weeks produced a sustained antihypertensive action of 20 to 40 mmHg. When CV-3317 (3 mg/kg) was combined with hydrochlorothiazide (10 mg/kg), its antihypertensive action was intensified in potency and duration. CV-3317 (30 mg/kg) induced a slight hypotension (5 to 10 mmHg) in normotensive rats, but had no effect on the blood pressure of 1-kidney, 1 clip hypertensive rats and on that of a low Renin type of DOCA/salt hypertensive rat. The antihypertensive activity of CV-3317 was more potent than that of captopril. In pithed SHR, the pressor response induced by an electrical stimulation of the preganglionic sympathetic nerve, but not the pressor response to norepinephrine, was attenuated by both agents (0.3 mg/kg, i.v.). Both agents may exert their antihypertensive action not only primarily by inhibiting the renin-angiotensin system, but also by inhibiting norepinephrine release from the sympathetic nerve terminals indirectly by reducing the formation of vascular angiotensin II.