Pharmacologic Studies of a New Antihypertensive Compound N-(o-Methoxyphenyl)-N'-(3-methoxypropyl)-piperazine Phosphate (HT1479)

Abstract
In a series of piperazines, N-(o-Methoxyphenyl) - N′-(3-methoxypropyl)-piperazine (HT1479) had potent hypotensive activity. Its homologue HT507 possesses similar hypotensive actions, but appears to be less potent and less adrenolytic. In nephrectomized animals duration of effect of HT1479 was much prolonged. This was also true in pithed vagotomized animals. The mechanism of hypotensive effect of this drug has not yet been fully established. While central effects of HT1479 may play a part in its hypotensive action, occurrence of a drop of blood pressure in pithed cat as well as experiments with triple manometer technic indicates that this is not the only mode of action. Paralysis of ganglia appears unlikely in view of the failure of HT1479 to block the effect of peripheral vagal stimulation of the heart. Peripheral adrenolytic properties of the drug may well play a role in its hypotensive action though they are too weak in low dosage to explain the total hypotensive potency. Other peripheral dilator actions could be involved. The effects upon heart rate have been inconsistent and the role of this organ in the overall effect cannot yet be fully appraised. HT1479 is now on clinical trial and will be reported later.