title: Effect of prostaglandin F2alpha (PGF2alpha), indomethacin, tamoxifen or estradiol-17beta on prostaglandin E (PGE), PGF2alpha and estradiol-17beta secretion in 88 to 90-day pregnant sheep.
abstract: Treatment with PGF2alpha plus estradiol-17beta aborts 90-day pregnant ewes, whereas PGF2alpha or estradiol-17beta alone does not abort ewes. The objective of this experiment was to evaluate whether tamoxifen, an estrogen receptor antagonist, estradiol-17beta, prostaglandin F2alpha (PGF2alpha), indomethacin, or some of their interactions affected ovine uterine/placental secretion of PGF2alpha, estradiol-17beta or prostaglandins E (PGE), because a single treatment with PGF2alpha and estradiol-17beta given every 6 h aborts 90-day pregnant ewes. Concentrations of PGF2alpha in uterine venous blood were increased (P < or = 0.05) by estradiol-17beta, PGF2alpha + estradiol-17beta, and PGF2alpha + tamoxifen, and decreased (P < or = 0.05) by indomethacin or PGF2alpha + indomethacin at 72 h when compared to the 0 h samples. Concentrations of PGE in uterine venous blood were decreased (P < or = 0.05) by indomethacin and PGF2alpha + indomethacin and increased (P < or = 0.05) by PGF2alpha + estradiol-17beta at 72 h when compared to the 0 h samples. Concentrations of PGF2alpha in inferior vena cava blood at 6 h were increased (P < or = 0.05) by PGF2alpha either alone or in combination with indomethacin, tamoxifen, or estradiol-17beta, which is due to the PGF2alpha injected. Concentrations of PGF2alpha in inferior vena cava blood in PGF2alpha + estradiol-17beta-treated 88- to 90-day pregnant ewes increased (P < or = 0.05) linearly over the 72-h sampling period and averaged 4.0 + 0.4 ng/ml. Concentrations of PGF2alpha in inferior vena cava blood of control, PGF2alpha, tamoxifen, PGF2alpha + indomethacin, PGF2alpha + tamoxifen, and estradiol-17beta-treated ewes did not differ (P > or = 0.05) and averaged 0.4 + 0.04 ng/ml. Profiles of PGE in inferior vena cava blood of 88- to 90-day pregnant ewes treated with vehicle, PGF2alpha, estradiol-17beta, tamoxifen, tamoxifen + PGF2alpha, or estradiol-17beta + PGF2alpha did not differ (P > or = 0.05). Concentrations of PGE in inferior vena cava blood of 88- to 90-day pregnant ewes treated with indomethacin or PGF2alpha + indomethacin were lower (P < or = 0.05) than in control ewes. Concentrations of estradiol-17beta in jugular venous plasma of PGF2alpha + estradiol-17beta-treated 88- to 90-day pregnant ewes increased linearly and differed (P < or = 0.05) from controls. Profiles of estradiol-17beta in jugular venous plasma of PGF2alpha, indomethacin, tamoxifen, and PGF2alpha + tamoxifen and PGF2alpha + indomethacin, estradiol-17beta, and controls did not differ (P > or = 0.05). It is concluded that treatment with a single injection of PGF2alpha and estradiol-17beta given every 6 h causes a linear increase in PGF2alpha and estradiol-17beta.
authors.affiliation: Dept. of Animal Sciences, University of Hawaii, Honolulu 96822, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Bridges
authors.forename: Y S
authors.initials: YS
authors.lastname: Weems
authors.forename: L M
authors.initials: LM
authors.lastname: Kim
authors.forename: B R
authors.initials: BR
authors.lastname: LeaMaster
authors.forename: D L
authors.initials: DL
authors.lastname: Vincent
authors.forename: C W
authors.initials: CW
authors.lastname: Weems
mesh_terms: D000021:Abortifacient Agents, Steroidal / Q000494:pharmacology*; D000028:Abortion, Induced / Q000662:veterinary; D000034:Abortion, Veterinary; D000818:Animals; D015237:Dinoprost / Q000097:blood / Q000494:pharmacology*; D004958:Estradiol / Q000097:blood*; D005260:Female; D007213:Indomethacin / Q000494:pharmacology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D011458:Prostaglandins E / Q000097:blood*; D012756:Sheep / Q000502:physiology*; D013629:Tamoxifen / Q000494:pharmacology*; D013997:Time Factors; D015149:Tocolytic Agents / Q000494:pharmacology*
chemical_list: D000021:Abortifacient Agents, Steroidal; D011458:Prostaglandins E; D015149:Tocolytic Agents; D013629:Tamoxifen; D004958:Estradiol; D015237:Dinoprost; D007213:Indomethacin