"Substance P" 의 고양이 심맥관계에 미치는 영향

초록

Substance P(SP), known as one of the potent hypotensive compounds, was examined for evaluation of the threshold dosage, action mechanism and action receptors in anesthetized cats. After injection of SP ranged from 100 ng to 0.3 ng per kg, nature of impulses of left ventricular pressure receptor(LVPR) was checked with arterial blood pressure and heart rates, compared to the group of propranolol premedication for blocking the reflex mechanism of pressure receptors. The results of this experimental study are as follow; 1. Threshold dosage of SP for hypotensive effect on the cat was 1 ng per kg. 2. Decreased impulses of LVPR and arterial pressure were noted as dose-dependent, but heart rates were not changed by SP. 3. Just after SP induced hypotension, heart rates were rapidly increased by the reflex mechanism of pressure receptors. On the other hand, such responses were not appeared in propranolol Premedication Above findings suggest that SP produced a depressor response by action on its own specific receptors of blood vessels, rather than the heart