[Sex characteristics of neuroendocrine effects of prenatal exposure to exogenous glucocorticoids].

ABSTRACT

The effects of hydrocortisone acetate treatment of rats during the last gestational week on neurochemical and morphological characteristics of the brain in early postnatal and mature offspring were studied. Disappearance of sexual differences both in aromatase and 5alpha-reductase activities and noradrenaline concentration in the preoptic area in 10-day old rats was found. Meanwhile a sexual dimorphism in serotonin metabolism emerged. In adult offspring, the prenatal exposure to glucocorticoids resulted in disappearance of sexual differences in neurocytes' nuclei volume in medial preoptic and suprachiasmatic nuclei. The adrenocortical reaction to noradrenaline infusion to the 3rd brain ventricle was absent in the experimental males and intensified in females. In males, adrenocortical reaction to restraint decreased while post-stress changes in hypothalamic noradrenaline concentration and hippocampal glutamate decarboxylase activity were not observed. In the similar experiments in females both the augmentation of adrenocortical reaction and inhibition of GABA-ergic system were revealed. The results obtained indicate the modifying effect of prenatal exposure to glucocorticoids on sexual dimorphism of neuroendocrine system.