Prolactinemia during the menstrual cycle. A possible role for prolactin in the regulation of ovarian function.

We measured the concentration of circulating prolactin (PRL) in the serum during ovulatory and anovulatory cycles of normoprolactinemic menstruating women. The results demonstrate that during the luteal phase of ovulatory cycles a significant increase of PRL is observed together with that of progesterone. On the contrary, in menstruating women with anovulatory cycles we could not detect these increases. These data, analyzed together with the concomitant changes of gonadotrophins secretion, suggest a possible luteotrophic action of PRL in humans during the menstrual cycle.