Inhibitory effects of 17beta-estradiol on spontaneous and activated contraction of rat uterus smooth muscle.
- Author:
Qin MA
1
;
Hong-Fang LI
;
Shan JIN
;
Xing-Cheng DOU
;
Ying-Fu ZHANG
;
Li-Xue ZHANG
;
Zhong-Rui DU
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Estradiol; pharmacology; Female; Muscle, Smooth; drug effects; Myometrium; drug effects; Rats; Rats, Sprague-Dawley; Uterine Contraction; drug effects
- From: Chinese Journal of Applied Physiology 2013;29(4):305-309
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo observe and compare the effects of 17beta-estradiol (EST) on the phasic and tonic contractile activities of the uterine smooth muscles of SD rats in vitro.
METHODSDifferent concentrations of 17beta-estradiol were added into the perfusion muscular sockets containing uterine smooth muscles of SD rats, and the activities of muscle contraction were recorded at the same time.
RESULTS17beta-estradiol had obvious depression effects on spontaneous rhythmic contraction of the uterine smooth muscles in a concentration-dependent manner, it could considerably decrease muscular tension, the mean amplitudes and frequencies of contractile waves (P < 0.01); it could also suppress the uterine contraction stimulated by KCl, CaCl2 or prostaglandin F2alpha (PGF2alpha). Based on the contraction of uterine smooth muscle stimulated by KCl, IC50 was 7.278 micromol/L and pD2 was -0.862 when calculated by linear regression method. 17beta-estradiol could also inhibit the maximal CaC12 contraction of uterine smooth muscle in the Ca2+ free Krebs solution, which the ECQ was 1.422 x 10(-3) mol/L, pD2 was 2.847 (control), but the E50 was 3.028 x 10(-3) mol/L, p2 was 2.519 (added with EST) when calculated by linear regression method.
CONCLUSIONThe depression effects of 17beta-estradiol on the spontaneous rhythmic contraction and activated contraction of the uterine smooth muscles of SD rats could be mediated through the blockage of C2+ influx through potential-dependent Ca2+ channels of plasma membrane.