Effect of PGF2α, indomethacin, tamoxifen, or estradiol-17β on incidence of abortion, progesterone, and pregnancy-specific protein B (PSPB) secretion in 88- to 90-day pregnant sheep☆

Autor: Yoshie S. Weems, R.G. Sasser, L. Kim, D.L. Vincent, B.R. LeaMaster, C.W. Weems, Phillip J. Bridges
Rok vydání: 1999
Předmět:
Zdroj: Prostaglandins & Other Lipid Mediators. 58:113-124
ISSN: 1098-8823
DOI: 10.1016/s0090-6980(99)00045-3
Popis: One objective of this experiment was to evaluate our hypotheses that estradiol-17beta regulates secretion of pregnancy specific protein B (PSPB) and that secretion of progesterone during pregnancy is regulated by a prostanoid by examining the effects of prostaglandin F2alpha (PGF2alpha), a luteolyic agent; indomethacin, a prostanoid synthesis inhibitor; tamoxifen, an estrogen receptor antagonist; estradiol 17-beta; and interaction of these factors on the incidence of abortion and progesterone and PSPB secretion. Another objective was to determine if there is a luteal source of PSPB. Weights of corpora lutea were decreased (Por = 0.05) by PGF2alpha, indomethacin, PGF2alpha + tamoxifen, PGF2alpha + indomethacin, and PGF2alpha + estradiol-17beta but not (Por = 0.05) by tamoxifen or estradiol-17beta alone. No ewe treated with PGF2alpha alone aborted (Por = 0.05). Forty percent of ewes treated with PGF2alpha + estradiol-17beta aborted (Por = 0.05), but ewes were not aborted by any other treatment within the 72-h sampling period. Profiles of progesterone in jugular venous blood differed (Por = 0.05) among control, indomethacin-, tamoxifen-, and PGF2alpha + indomethacin-treated ewes. Progesterone in jugular venous blood of control ewes decreased (Por = 0.05) by 24 h, followed by a quadratic increase (Por = 0.05) from 24 to 62 h. Progesterone in jugular venous blood of indomethacin-, PGF2alpha-, PGF2alpha- + tamoxifen-, PGF2alpha + indomethacin-, PGF2alpha + estradiol-17beta-, and tamoxifen-treated ewes was reduced (Por = 0.05) by 18 h and did not vary (Por = 0.05) for the remainder of the 72-h sampling period. Progesterone in vena cava and in uterine venous blood was reduced (Por = 0.05) at 72 h in PGF2alpha-, indomethacin-, tamoxifen-, PGF2alpha + indomethacin-, PGF2alpha + tamoxifen-, and PGF2alpha + estradiol-17beta-treated ewes. Weights of placentomes did not differ among treatment groups (Por = 0.05). Profiles of PSPB in inferior vena cava blood differed (Por = 0.05) among control, estradiol-17beta-, indomethacin-, tamoxifen-, PGF2alpha + indomethacin-, and PGF2alpha + tamoxifen-treated 88- to 90-day pregnant ewes. Concentrations of PSPB in inferior vena cava blood were increased (Por = 0.05) in indomethacin-, estradiol-17beta-, tamoxifen-, PGF2alpha + tamoxifen-, and PGF2alpha + indomethacin-treated 88- to 90-day pregnant ewes within 6 h and did not vary (Por = 0.05) for the remainder of the 72-h sampling period. Concentrations of PSPB in uterine venous blood of indomethacin-, tamoxifen-, PGF2alpha + tamoxifen-, and PGF2alpha + indomethacin-treated ewes were greater (Por = 0.05) at 72 h than at 0 h. PSPB in ovarian venous blood did not differ (Por = 0.05) adjacent or opposite to the ovary with the corpus luteum. It is concluded from these data that estrogen regulates placental secretion of PSPB and that a prostanoid, presumably prostaglandin E, regulates placental secretion of progesterone during 88-90 days of gestation in sheep and that there is no luteal source of PSPB.
Databáze: OpenAIRE
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