Endothelin-1 and endothelin receptors are present in the sheep uterus and conceptus at implantation.

摘要: Previous studies have demonstrated that endothelin is present in the ovine endometrium and increases at around expected time of implantation. To characterize further uterine establishment pregnancy sheep, was measured by radioimmunoassay flushings obtained during oestrous cycle pregnant ewes up to implantation (day 16). During cycle, highest amounts were on day 14 (1.1 +/- 0.2 ng endothelin/uterus). early pregnancy, basal levels (0.5-0.6 endothelin/uterus) for first 10 days then increased similar those found equivalent stage cycle. On 15 16 content lumen significantly (P < 0.05) higher concentrations (2.9 0.4 when compared with non-fertile The principal isoform endothelin-1, as determined reverse-phase HPLC. Endothelin released principally purified endometrial epithelial cells culture, barely detectable stromal or conceptus tissue, which consistent epithelium being source lumen. binding sites myometrium, specific 125I-labelled saturable displaced endothelin-1. Both endothelinA B sub-types receptors biphasic displacement endothelin-1 endothelinB agonist BQ3020. These localised luminal glandular vasculature myometrium shown autoradiography. also In 20 conceptus, immunostaining heart, trophoblast uninucleate but not binucleate cells, fetal membranes. This may represent receptor sites. It concluded play an important role paracrine regulation rapid embryo development, placentation.