Pharmacological profile of ME3221, a novel angiotensin II receptor antagonist.

The pharmacological profile of a new surmountable angiotensin AT1 receptor antagonist, ME3221, 3-methoxy-2,6-dimethyl-4-[[2'-(1H-tetrazol-5-yl)-1,1'-biphenyl-4- yl]methoxy]pyridine, was studied in several animal models, and was compared with that of losartan. EF2831, 3-hydroxy-2,6-dimethyl-4-[[2'-(1H-tetrazol-5-yl)-1,1'-biphenyl-4- yl]methoxy]pyridine, a metabolite of ME3221, is also a surmountable angiotensin AT1 receptor antagonist, whose potency was 1/30 that of ME3221 in vitro, but equal to or 1/3 of that of ME3221 in in vivo experiments. In rats and marmosets, ME3221 antagonized angiotensin II-induced pressor responses, but did not affect bradykinin-induced depressor responses. ME3221 lowered the blood pressure in renal hypertensive rats and spontaneously hypertensive rats (SHR), and its ED25 value was 3 times that of losartan. Repeated administration of ME3221 to SHR had a stable and long-lasting antihypertensive effect without influencing heart rate. Thus ME3221, like losartan, may be useful in the treatment of renal and essential hypertension.