Hormone receptor control of pulsatile secretion of PGF2α from the ovine uterus during luteolysis and its abrogation in early pregnancy

摘要: Abstract Studies on the control of PGF2α secretion by hormone receptors in ovine uterus based vivo infusion experiments autotransplanted are summarized. In addition, direct measurement receptor dynamics for oestradiol-17β, progesterone and oxytocin under experimental conditions reported. Investigation antiluteolytic effect early pregnancy sheep was approached two ways: (a) studies antiprostaglandin secreting embryo (b) a putative luteoprotective embryo. former study, samples uterine venous plasma collected hourly from 5 days 12 to 17 postmating failed reveal presence any major peaks secretion. latter approach, several substances were examined their ability block luteolytic given as separate hour-long pulses over 25 h into arterial supply ovary. These included: day 14–15 pregnant sheep, PGE2, prolactin, LH, placental lactogen porcine relaxin. no case convincing demonstrated suggesting that may be more important these mechanisms. Experiments performed investigate circulating levels endogenous monitoring intramyometrial pressure continuous basis conscious sheep. revealed periods intense activity at intervals 5.5 6.5 hours 14 16 cyclic animal, but not animal. Based results recent reports production corpus luteum, hypothesis is presented explain episodic pulsatile including possible mechanism its abrogation during pregnancy.