Relationship of prolactin and gonadotrophic hormones in regulation of the ovarian function

Circulating concentration of the LH, FSH, prolactin (PRL), oestradiol-17 beta (E2) and progesterone (P) in serum were investigated in women with normal cycles and proven fertility, with irregular cycles and infertility and with primary or secondary amenorrhea in order to understand the relationship of the prolactin and gonadotrophic hormens in regulation of the ovarian function. The results indicate that hyperprolactinemia inhibits the pituitary to release the midcycle LH surge in response to the positive feedback action of the elevated oestrogen at the midcycle. The elevated LH and FSH levels found in the cases of the secondary amenorrhea is the indication of the absence of the steroid negative feedback due to the ovarian failure. Prolactin does not seem to play a role on the manifestation of either primary or secondary amenorrhea.