Secretion of progesterone, estradiol-17 beta and androstenedione by porcine uterine explants during the mid-luteal phase of the estrous cycle and luteolysis

摘要

Steroid hormones are key regulators of processes that occur within the female reproductive system during the estrous cycle and pregnancy. So far, studies concerning the pig uterus as a steroidogenic organ were performed on separated endometrial and myometrial tissue slices. The aim of our study was to determine the level of the following steroid hormones secretions: progesterone (P-4), estradiol (E-2), and androstenedione (A(4)) in porcine (not separated) uterine explants at days 10-12 (the mid-luteal phase) and days 14-16 of the estrous cycle (the stage of luteolysis), as well as to investigate whether secretion of P-4, E-2 and A(4) is regulated by steroids, oxytocin (OT), arachidonic acid (AA, the substrate for the synthesis of prostaglandins), forskolin (FSK, an activator of adenylate cyclase) and cAMP (cyclic adenosine monophosphate, second messenger). This study showed diverse primary secretion of P-4 and E-2 in the pig uterus during the luteal phase and luteolysis. The secretion of P-4 and E-2 was higher at the days 10-12 than days 14-16 of the estrous cycle. The present observation confirmed involvement of P-4, E-2 in the control of pig uterus steroid hormones release. Moreover we demonstrated that AA, FSK and cAMP enhanced the production of P-4, E-2, and A(4) in the pig uterus during the examined periods.