Impact of the UV-B filter 4-(Methylbenzylidene)-camphor (4-MBC) during prenatal development in the neuroendocrine regulation of gonadal axis in male and female adult rats.

4-(Methylbenzylidene)-camphor (4-MBC), a UV-B ray filter, is an endocrine disruptors (ED). Our goal was to study the effect of 4-MBC on the neuroendocrine parameters that regulate reproduction in adult female and male rats that received this disrupter during prenatal development. The 4-MBC was administered (sc) to female rats (FO) since pregnancy onset, in doses of 100mg/kg every other day. The litters (F1) were sacrificed at 70 days to determine gonadotrophin serum levels and also GnRH and the amino acids glutamate, aspartate and GABA release from the hypothalamus. The male litter rats (F1) present at adult age a decrease in serum LH and FSH concentration and so also GnRH, excitatory amino acids and GABA hypothalamic secretion. The female litters (F1) rats present at adult age an increase in serum LH and FSH concentration, whereas hypothalamic GnRH release was not modified. In these animals a significant increase of hypothalamic aspartate release as well as GABA secretion decrease were observed. Glutamate secretion was not modified. All these changes were accompanied by an advance (3 days) on the vaginal opening in 4-MBC rats group. In conclusion, prenatal administration of 4-MBC disrupts the gonadal axis in a sexual dimorphic mode that could be connected with the physiological sexual differences in the development of gonadotrophin secretion hypothalamic control mechanisms.