STIMULATION OF PITUITARY FSH RELEASE IN IMMATURE FEMALE RATS BY PROLACTIN IMPLANT IN MEDIAN EMINENCE

Prolactin was implanted into the median eminence of 21-day-old female rats and its effects on pituitary FSH secretion were studied. Rats killed 5 or 8 days after implantation showed a significant reduction in pituitary FSH concentration as compared with control rats implanted with cholesterol, or with control rats given implants of other hormones in amounts stated to he present in the prolactin preparation. Examination of the ovaries and uterus indicated that prolactin implantation resulted in follicular and uterine endometrial growth and increased uterine weight. These findings indicate that an implant of prolactin in the median eminence results in stimulation of FSH release in prepuberal rats. © 1969 S. Karger AG, Basel.