Sex hormone effects in non-pregnant rat and human myometrium.
OBJECTIVE
To study effects of sex hormones on spontaneous contractility and on the effects of depolarizing agent potassium chloride (KCl), M-cholinoceptor and prostaglandin receptor agonists on non-pregnant rat and human uterine tissues.


METHODS
Uterine rings from ovariectomized rats treated with sex hormones or placebo, and uterine strips from premenopausal and postmenopausal women were equilibrated in Krebs buffer (t=37 degrees C, pH approximately 7.4) for isometric tension recordings. Spontaneous contractile activity and contractions in response to KCl, eicosanoids, and acetylcholine were compared.


RESULTS
In tissues from ovariectomized rats, spontaneous contractility was increased, while KCl-induced contractions were decreased. Treatment with 17beta-estradiol, but not progesterone, inhibited spontaneous contractions, but potentiated KCl evoked contractions. Treatment with 17beta-estradiol did not influence responses to prostanoids in ovariectomized rats, while treatment with both sex hormones restored decreased the responses. Spontaneous contractility and responses to KCl were less in uterine tissues from postmenopausal versus premenopausal women. Hormone replacement therapy partly restored the responses to KCl, prostanoids, and acetylcholine.


CONCLUSIONS
Ovarian steroids modulate spontaneous contractile activity, responses to depolarization, prostanoids and M-cholinoceptor activation in non-pregnant rat and human uterine tissues in vitro.
Vedernikov
Yuri P
YP
Department of Obstetrics and Gynecology, Division of Reproductive Sciences, University of Texas Medical Branch, 301 University Building, Galveston, TX 77555-1062, USA. yvederni@utmb.edu
Hartke
James R
JR
de Long
Mitchell A
MA
Saade
George R
GR
Garfield
Robert E
RE
D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D000818:Animals; D015237:Dinoprost / Q000494:pharmacology; D015232:Dinoprostone / Q000031:analogs & derivatives* / Q000494:pharmacology; D004357:Drug Synergism; D004958:Estradiol / Q000494:pharmacology; D015914:Estrogen Replacement Therapy; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D000077338:Latanoprost; D008875:Middle Aged; D009215:Myometrium / Q000187:drug effects*; D010052:Ovariectomy; D010919:Placebos; D017698:Postmenopause; D011189:Potassium Chloride / Q000494:pharmacology; D017697:Premenopause; D011374:Progesterone / Q000494:pharmacology; D011461:Prostaglandins F, Synthetic / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014590:Uterine Contraction / Q000187:drug effects
C092396:17-phenyltrinorprostaglandin E2; D012739:Gonadal Steroid Hormones; D010919:Placebos; D011461:Prostaglandins F, Synthetic; D011374:Progesterone; D004958:Estradiol; D011189:Potassium Chloride; D000077338:Latanoprost; D015237:Dinoprost; D015232:Dinoprostone; D000109:Acetylcholine