Gonadotropin releasing hormone (GnrH) stimulates immunoreactive lactotrope differentiation.

To study lactotrope differentiation in the fetal rat, immunocytochemistry was performed on pituitary primordia explanted from 13-day-old fetuses and cultured in different synthetic media until the equivalent of 21 days. Lactotropes were detected only by antirat prolactin antiserum when the synthetic medium was enriched with GnRH (10(-9)M). These results indicate that lactotrope differentiation may partly depend on stimulatory factors such as GnRH.