PULSATILE GNRH-STIMULATED LH-RELEASE FROM THE HUMAN FETAL PITUITARY INVITRO - SEX-ASSOCIATED DIFFERENCES

An in‐vitro perifusion system was utilized to examine LH release from human fetal (19–24 weeks gestation) anterior pituitaries during repetitive GnRH stimulations. Pituitaries (five male, four female) were dissected into halves, and one hemipituitary of each pair was stimulated with 10‐min pulses of 1 nm GnRH administered at 60‐min intervals over 24h, whereas the matching hemipituitary received pulses of medium alone. Basal (no GnRH stimulation) LH release from female hemipituitaries was significantly (P < 0.01) greater than from male hemipituitaries, and the amplitude of LH release associated with GnRH pulses was sixfold greater (P < 0.001) with female hemipituitaries. Furthermore, the magnitude of LH release associated with individual GnRH pulses was significantly (P < 0.001) enhanced during the course of female hemipituitary perifusions, but not during perifusion of male hemipituitaries. These studies demonstrate that LH secretion by the female, but not male, mid‐gestational human fetal pituitary is increased in response to a physiological pattern and interval of repeated pulsatile GnRH stimulation in vitro. © 1990 Blackwell Scientific Publications Ltd.