Trilostane but not prostaglandin F2alpha (PGF2alpha) or cortisol aborts 90-day-pregnant lutectomized sheep.
Ewes were lutectomized and treatments were started 72 h later. Pregnant ewes were treated with vehicle; prostaglandin F2alpha (PGF2alpha); cortisol (C); trilostane (TR), a 3beta-hydroxy-steroid dehydrogenase inhibitor; PGF2alpha + C; TR + PGF2alpha; TR + C, or TR + PGF2 + C. TR, TR + PGF2alpha, TR + C, and TR + PGF2alpha + C aborted (P < or = 0.05) all ewes receiving TR. One ewe treated with PGF2alpha aborted (P > or = 0.05). The average time to abortion of TR-treated ewes was 50.8 h (P < or = 0.05) after initiation of treatments. All aborted ewes had retained placentas (P < or = 0.05) except one ewe in the TR + PGF2alpha, treatment group. TR was given every 12 h starting at 72 h postlutectomy until 96 h postlutectomy. TR reduced (P < or = 0.05) progesterone. Estradiol-17beta was increased (P < or = 0.05) 2 h after the first two TR treatments and declined 2 h later and was followed by a sustained increase (P < or = 0.05) in estradiol-17beta, which was coincident with the onset of abortions. Estradiol-17beta was increased (P < or = 0.05) by PGF2alpha but did not decrease (P > or = 0.05) placental secretion of progesterone. It is concluded that TR but not PGF2alpha is an abortifacient in 90-day-pregnant lutectomized ewes and that abortion occurs only when there is a decrease in circulating progesterone and an increase in circulating estradiol-17beta.
Weems
Y S
YS
Department of Animal Science, University of Hawaii, Honolulu 96822, USA.
Vincent
D L
DL
Lemme
C
C
Weems
C W
CW
D015096:3-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors; D000021:Abortifacient Agents, Steroidal / Q000494:pharmacology*; D000028:Abortion, Induced / Q000662:veterinary; D000034:Abortion, Veterinary; D000818:Animals; D003338:Corpus Luteum / Q000502:physiology / Q000601:surgery; D013196:Dihydrotestosterone / Q000031:analogs & derivatives* / Q000494:pharmacology; D015237:Dinoprost / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004958:Estradiol / Q000097:blood; D005260:Female; D006854:Hydrocortisone / Q000494:pharmacology; D009929:Organ Size; D010920:Placenta / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects*; D011374:Progesterone / Q000378:metabolism; D012756:Sheep; D013997:Time Factors
D000021:Abortifacient Agents, Steroidal; D004791:Enzyme Inhibitors; D013196:Dihydrotestosterone; D011374:Progesterone; D004958:Estradiol; D015237:Dinoprost; D015096:3-Hydroxysteroid Dehydrogenases; C009954:trilostane; D006854:Hydrocortisone