EFEITO DA EXPOSIÇÃO PERINATAL AO HERBICIDA GLIFOSATO-ROUNDUP NA DIFERENCIAÇÃO SEXUAL E ENDOCRINOLOGIA REPRODUTIVA

Abstract

Glyphosate, a herbicide Roundup® is widely used and considered a potent endocrine disrupter when administered to rats in the pre-pubescent. This study aimed to evaluate the effects caused by this herbicide in the offspring of females treated during the perinatal period. Were used as experimental models 38 Wistar rats (Rattus norvegicus) from males 6 females. Of these, 25 were part of the treated group, where mothers received the dose of glyphosate in Roundup ® 50mg/kgPV Transorb by gavage and 13 took part in the control group, where mothers also received distilled water by gavage. The administration period was the 18th day of gestation (D18) until five days after the delivery (D25). This period is characterized as the "critical period" of sexual differentiation of hypothalamus, where the conversion of testosterone to estradiol makes the hypothalamus acyclic. We evaluated the evolution of body weight, weight and age at puberty, weight of testes, epididymis and seminal vesicles, sperm count, daily sperm production per testis, sperm reserves, sperm transit time, testicular morphology (tubular and luminal diameter and thickness epithelial tubules), serum FSH, LH, testosterone and estradiol and finally sexual orientation. The statistical analysis were used to test Kolomogorov-Smirnov normality, homoscedasticity of the Barlet and analysis of twoway variance (MANOVA). The herbicide Roundup ® Transorb Glyphosate did not affect the animals` body development. The age at which studied the offspring reached puberty was changed, the animals treated with the herbicide mothers reached puberty earlier and therefore also had less weight. The testes weight did not change, since the seminal vesicles and epididymis had drained to heavier in the animals receiving treatment with the herbicide. The number of spermatids per testis and per gram of testis, daily sperm production per testis and sperm reserves in the head + body segment of the epididymis were higher in the treated group. The sperm transit was faster in the segment in the tail of the epididymis treated animals. The animals in both groups (treated and control) showed no changes in total testis tubule diameter, however, the epithelial thickness was greater in the treated group and greater luminal diameter in the control group. There were no changes in serum hormone FSH, as LH, testosterone and estradiol were found in higher concentrations in treated animals. Sexual orientation showed that animals treated group showed a longer stay in the area of the total female and higher scores of sexual preference by females. It can be concluded that this herbicide is likely an endocrine disrupter in the "critical period" of hypothalamic sexual differentiation to male rats, which causes morphological changes and sexual orientation of animals in adulthood.