Inhibitory actions of steroid hormones on isolated smooth muscles

Abstract

Inhibitory activities of steroid hormones and their related compounds were tested on the contraction of isolated guinea-pig ileum induced by acetylcholine (ACh), BaCl2, histamine, 5-hydroxytryptamine creatinine sulfate complex, and bradykinin, and of isolated rat uterus by ACh, BaCl2 and oxytocin. Compounds tested were 3 androgens, 5 estrogens, 4 gestagens, and 5 corticoids. All of them, except pregnanediols, had more or less inhibitory action on the contraction of smooth muscles. Among them, androsterone, dehydroepiandrosterone, estradiol, synthetic estrogens, and deoxycorticosterone were stronger than others and had almost the same order of activity as that of papaverine on guinea-pig ileum. Estradiol, diethylstilbestrol, and hexestrol showed a specific inhibition on the oxytocin contraction of isolated rat uterus. These results suggested that androsterone, dehydroepiandrosterone, and estradiol among the metabolites of steroid hormones may be some of inhibitory principles in human urine.