Effects of ethanol intake and noise exposure on adolescent rat hippocampal reactive oxygen species and glutaredoxins

MOLINA, SJ; LIETTI, AE; CARREIRA CARO, CS; D'ALESSIO, L; BUJÁN, GE; GUELMAN, LR

Chicago

Congreso; 50th Annual Meeting of the Society for Neuroscience (SFN), Neurosciencie 2021; 2021

Society for Neuroscience

Human adolescents usually consume ethanol (EtOH) for recreational purposes in social gatherings, bars and concerts, places where they are also often exposed to noise of high intensity. According to published animal experimental data, both stimuli presented separately might generate an imbalance in hippocampal (HC) oxidative system that could underlay HC-dependent behavioral alterations. Thus, the aim of this work was to test the effects of EtOH intake followed by noise exposure on the oxidative state of the HC in adolescent rats.Wistar rats of both sexes (28-days-old) were subjected to voluntary 10% EtOH intake using the ?two-bottle choice drinking-in-the-dark? paradigm, during 4h/d, for 4 days. After the last session, rats were exposed to noise (95-97 dB, 2h). Finally, HC was dissected to assess the levels of reactive oxygen species (ROS) and catalase activity (CAT) through biochemical techniques as well as the antioxidant enzyme glutaredoxin-1 (Grx-1) through western blot analyses.Results showed an increase in ROS levels after EtOH intake and a decrease in Grx-1 levels after noise exposure in the HC of female rats, when compared with sham animals. In contrast, a decrease in ROS levels after noise exposure was found in males HC. When EtOH intake was followed by noise exposure, a significant decrease in ROS levels was found, both in males and females HC and an increase in Grx-1 was found only in males HC. Finally, nonsignificant differences were observed in CAT among groups in comparison to sham animals, either in females or males.These findings suggest that EtOH intake and noise exposure might affect HC oxidative state in a sex-dependent way. When both stimuli were presented separately, female rats appear to be more sensitive to EtOH, whereas males showed changes only when exposed to noise. However, when both agents were presented together, both sexes seem to be equally affected, suggesting that the combination of both stimuli might unmask any effects that would not have been observed with each agent individually. Finally, the finding of an increase in Grx-1 levels when ROS levels are decreased, observed only in males, might reveal a relevant role for this enzyme aimed to compensate for an oxidative imbalance triggered by the environmental stressors.