Study on serotoninergic mechanisms of compensatory ovarian hypertrophy in rats.

The increase of brain serotonin level following the treatment of hemicastrate adult female rats with L-tryptophane or Agr-1240 inhibits the compensatory ovarian hypertrophy (COH). The blockade of central serotoninergic receptors with typindole abolished the suppressive effect of estrogen on COH. The administration of L-DOPA abolished this effect of typindole. The dose-related inhibitory effect of melatonin on COH was shown. Serotoninergic systems are suggested to participate in the realisation of the negative feedback action of estrogen. The threshold of the hypothalamo-pituitary sensitivity to the suppressive estrogen effect is elevated in both pinealectomized and constant light-exposed rats.