Efeitos neuroendócrinos e comportamentais do hormônio estrogênio em Zebrafish

Abstract

The estrogen hormone is considered an endocrine disrupter, and is more present than ever in the daily life of humans, in Brazil, this hormone is found in concentrations between 3 and 54 ng/L in water sources, just like some drugs, estrogen may not be fully metabolized by organisms and may be excreted either in their original or organically complex form to water residue systems. Considering that less than half of the Brazilian population has a sewage network, and a smaller portion has access to treated sewage, the estrogen 17α-ethinylestradiol, used inoral contraceptives, is very difficult to remove from the water we sought to evaluate whether the synthetic hormone 17α-ethinylestradiol affects the neuroendocrine axis of stress and behavior using adult Zebrafish as a model organism at concentrations of 0.05, 0.5, 5, 50 and 75 ng / L in relation to the control evaluating the half-life of this compound and its bioaccumulation in animal tissues. For this, we evaluated the activity of the enzyme acetylcholinesterase, quantified the cortisol levels in the whole body of the fish, evaluated the social behavior, the behavior of the aggressive type and the locomotor parameters to analyze the anxiety of the exposed animals. We note that exposure to the synthetic hormone 17α-ethinylestradiol, even at low concentrations, affected behavioral and neuroendocrine variables of the model organism being even more expressive in organisms submitted to stress. Considering the presence of the hormone in the water, it is concluded that 17α-ethynyloestradiol affects the central nervous system and the endocrine system, which is evidenced by the behavior alterations, making the species more susceptible to predation, promoting negative effects on reproduction and jeopardizing the species in the ecosystem.