Oestradiol-17 beta both inhibits and stimulates myometrial activity in ewes in vivo.
Spontaneous intrauterine pressure cycles were abolished for periods of several hours in ovariectomized non-pregnant ewes within 8 h of an injection of 50 micrograms oestradiol-17 beta. Following the quiescent period, a phase of intense uterine activity ensued for several hours before again being replaced by several hours of quiescence. This active/inactive cycle disappeared after 2-4 days if further daily injections of oestradiol were not given. During the quiescent periods the uterus retained its responsiveness to oxytocin and PGF-2 alpha. Increasing the dose of oestradiol failed to prolong the periods of quiescence.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D005260:Female; D011312:Pressure; D012756:Sheep / Q000502:physiology*; D013997:Time Factors; D014590:Uterine Contraction / Q000187:drug effects*
D004958:Estradiol