Relaxin inhibits myometrial activity in the ovariectomized non-pregnant ewe.
Myometrial activity was abolished abruptly but reversibly in 4 out of 5 ewes by the intravenous injection of 1 mg (500 GPU) porcine relaxin. Recovery began only after about 90 min and was not complete until 3-4 h after the injection. During the relaxin-induced inhibition the myometrium responded to oxytocin administered intravenously in doses of 250 mU. One ewe received intrauterine infusions of 2.5 and 5.0 microgram PGF-2 alpha per min during the period of relaxin inhibition: the former dose evoked a slight, and the latter a marked, response from the myometrium. The rate of rise of intrauterine pressure and the mean amplitude of pressures cycles were significantly depressed at 1, 1.5 and 2 h after the relaxin injection.
D000818:Animals; D002369:Castration; D005260:Female; D009215:Myometrium / Q000187:drug effects / Q000502:physiology; D010121:Oxytocin / Q000494:pharmacology; D011312:Pressure; D011460:Prostaglandins F / Q000494:pharmacology; D012065:Relaxin / Q000494:pharmacology*; D012756:Sheep; D014590:Uterine Contraction / Q000187:drug effects*
D011460:Prostaglandins F; D010121:Oxytocin; D012065:Relaxin