Effects of a high concentrated estrogen and progesterone on the contractile mechanism in the uterine smooth muscles

Abstract

1. The effects of a high concentrated estrogen and progesterone were studied on the contractile activities in isolated myometrial strips from humans and rats by recording isometric tension development. The contractions were reduced by 10−5~3 X10−5M estrone (E1) estradiol (E2), estriol (E3), and progesterone (P) in non pregnant human uterus. The contractions were reduced by 10–6—10−4M E1, E2, E3and P in non pregnant rat uterus. The contractions induced by 10−8— 10−5M PGE2and PGF2α were reduced by 10–5M E2and P in non pregnant rat uterus. The contractions induced by 10−10— 3 X 10−8M oxytocin were reduced by 10–5M E2and P in non pregnant rat uterus. The contractures induced by 10–4~10−2M Ca2+were reduced by 10–5M E2and P in non pregnant rat uterus. 2. The effects of a high concentrated estrogen and progesterone were studied on Ca2+influx and Ca2+release from intracellular Ca store in the depolarized uterine smooth muscle cells from non pregnant rats. The inhibitory effects on the contractility by 3 X10−6~ 3 X10−5M E2, E3and P supported the suggestion that estrogen and progesterone have an inhibitory action on Ca2+influx and Ca2+release from intracellular Ca store. © 1986, Japan Society of Smooth Muscle Research. All rights reserved.