The role of monoamines in female puberty.

The estradiol positive feedback mechanism appears to become mature between days 10 and 20 after birth. Rising serum prolactin levels between day 20 after birth and puberty are correlated with high hypothalamic norepinephrine turnover. High prolactin levels stimulate hypothalamic dopamine (DA) turnover, which may actively inhibit hypothalamic luteinizing hormone-releasing hormone (LHRH) release. Hypothalamic DNA receptor sensitivity is high in 10- to 20-day-old rats and gradually decreases between day 20 after birth and puberty. The reason for this desensitization may be the high hypothalamic DA turnover. This may result in a less strong inhibition of LHRH release allowing the positive feedback action of estradiol to elicit the first preovulatory luteinizing hormone (LH) surge initiating puberty.