title: Advancement of uterine secretion of prostaglandin E2 by treatment with progesterone and transfer of asynchronous embryos.
abstract: Effects of treatment with progesterone early after estrus and the age of the blastocyst in the uterus on day-6 postestrus on uteroovarian venous concentration of prostaglandin E2 (PGE2) during days 7-12 postestrus were examined. At estrus, 24 ewes were assigned randomly to mating with fertile rams and daily injections of progesterone from days 1-3 postestrus, mating with fertile rams and daily injections of vehicle from days 1-3 postestrus, no mating, injection of progesterone from days 1-3 postestrus and transfer of a day-10 blastocyst into the uterus on day-6 postestrus, and no mating, injection of vehicle from days 1-3 postestrus and transfer of a day-10 blastocyst into the uterus on day-6 postestrus. PGE2 increased beginning on day 8 in progesterone-treated ewes that received a day-10 blastocyst on day-6 postestrus, but did not increase until day 12 in mated ewes with confirmed pregnancy. PGE2 remained at basal concentrations in mated progesterone-treated ewes (with a day-6 blastocyst on day-6) and showed only a transient rise on day-11 in vehicle-treated ewes which received a day-10 blastocyst on day-6 postestrus. It is concluded that progesterone regulates the ability of the uterus to release PGE2 in response to a blastocyst of appropriate age.
authors.forename: D L
authors.initials: DL
authors.lastname: Vincent
authors.forename: S
authors.initials: S
authors.lastname: Meredith
authors.forename: E K
authors.initials: EK
authors.lastname: Inskeep
mesh_terms: D000818:Animals; D015232:Dinoprostone; D004624:Embryo Transfer; D004971:Estrus; D005260:Female; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology*; D011458:Prostaglandins E / Q000378:metabolism*; D013997:Time Factors; D014599:Uterus / Q000187:drug effects / Q000378:metabolism*
chemical_list: D011458:Prostaglandins E; D011374:Progesterone; D015232:Dinoprostone