FACTORS INFLUENCING IN VITRO SYNTHESIS OF PROGESTERONE12

Abstract

Pituitary homogcnates from gilts at different stages of the estrous cycle and gestation did not stimulate or inhibit in vitro progesterone synthesis by gilt luteal tissue in Krebs-Ringer bicarbonate buffer medium containing 200 mg. glucose. Non-pituitary gonadotrophins, PMS and HCG; relaxin; and oxytocic materials, Syntocinon and Purified Oxytocic Principle, had no effect on in vitro synthesis of progesterone by swine luteal tissue. Ovine lactogenic hormone (prolactin, uteotrophic hormone or LTH) had no detectable effect on in vitro or in vivo luteal function. Subtotal hysterectomy prolonged the functional life of gilt corpora lutea as indicated by progesterone content and capacity of tissue to synthesize the hormone in vitro. Endometrial filtrates from days 12 and 13 of the estrous cycle increased in vitro progesterone synthesis by luteal tissue whereas filtrates from days 16 and 18 showed a definite inhibitory effect on hormone production.