The effects of ovariectomy and ovarian steroids on uterine oxytocin receptors in the anoestrous ewe

Abstract

The effects of treatment with progesterone, oestradiol-17β or the presumptive oestrogen agonist Tamoxifen on the concentrations of uterine oxytocin receptors (OTr) were investigated in Merino ewes during the anoestrous season. Three groups of ewes were ovariectomised (Ovx) and subsequently given progesterone (n = 5), oestradiol-17β (n = 4) or no treatment (control-Ovx, n = 5) for 6 days. Two groups of ewes were sham-operated and given either Tamoxifen (n = 5) or no treatment (control-intact, n = 5) for 6 days. All ewes were then given an intravenous (i.v.) injection of oxytocin (10 IU) to determine the prostaglandin (PG)F2α metabolite, 13, 14-dihydro-15-keto-PGF2α (PGFM) response. Immediatel..