The regulation in vitro of placental release of human chorionic gonadotropin, placental lactogen, and prolactin: effects of an adrenergic beta-receptor agonist and antagonist.

An experimental model for the study of placental tissue release of hormones has been explored. It has been shown that the trophoblast in Ringer-glucose solution releases human placental lactogen (hPL) and chorionic gonadotropin (hCG) in a time- (10 to 180 minutes) and temperature- (4 degrees and 37 degrees C) dependent manner. The adrenergic beta-receptor agonist terbutaline caused an increase in hCG secretion but did not affect hPL. With a mixed trophoblast/decidua preparation, prolactin release was not found to be time and temperature related. Terbutaline increased prolactin release and timolol decreased it. The data suggest tha adrenergic mechanisms are involved in hCG and prolactin secretion from the placenta.