Pharmacological studies on the vascular system of the placenta from humans

Abstract

In our experiments testing the effect of various vasodilators and vasoconstrictors on the placenta from humans the following results were obtained : 1) Isoproterenol, phenoxybenzamine, ACh, pilocarpine, atropine, papaverine, sodium nitrite, ergotamine, barium chloride, oxytocin, quinine, caffeine, nicotine and ephedrine all had mild vasoconstricting action, whereas adrenaline, noradrenaline, 5-HT and histamine had considerably stronger action. 2) Blood vessels appeared to be extremely sensitive to changes in the levels of O2, CO2 and nitrogen of perfusion fluid. 3) During states of hypercapnia, hypoxia and anoxia, a vasodilatation was observed. Conversely, a vasoconstricting effect was observed in the presence of hyperoxia. © 1974, The Japanese Pharmacological Society. All rights reserved.