A hypotensive effect of LL-1418 was demonstrated in normal and hypertensive conscious dogs and rats.In anesthetized rats, rabbits, guinea pigs, cats, and dogs, LL-1418 decreased systemic blood pressure, heart rate, and peripheral resistance.High doses (30 mg./kg., i.v.) in anesthetized dogs decreased cardiac output and heart rate, while systemic vascular resistance and pulse pressure were only slightly affected.