Hydrogen sulfide prevents the vascular dysfunction induced by severe traumatic brain injury in rats by reducing reactive oxygen species and modulating eNOS and H2S-synthesizing enzyme expression

Abstract

AimTo assess the effects of subchronic administration with NaHS, an exogenous H2S donor, on TBI-induced hypertension and vascular impairments. Main methodsAnimals underweministration does not prevent the body weight loss but slightly imnt a lateral fluid percussion injury, and the hemodynamic variables were measured in vivo by plethysmograph method. The vascular function in vitro, the ROS levels by the DCFH-DA method and the expression of H2S-synthesizing enzymes and eNOS by Western blot were measured in isolated thoracic aortas at day 7 post-TBI. The effect of L-NAME on NaHS-induced effects in vascular function was evaluated. Brain water content was determined 7 days after trauma induction. Body weight was recorded throughout the experimental protocol, whereas the sensorimotor function was evaluated using the neuroscore test at days −1 (basal), 2, and 7 after the TBI induction. Key findingsTBI animals showed: 1) an increase in hemodynamic variables and ROS levels in aortas; 2) vascular dysfunction; 3) sensorimotor dysfunction; and 4) a decrease in body weight, the expression of H2S-synthesizing enzymes, and eNOS phosphorylation. Interestingly, NaHS subchronic administration (3.1 mg/kg; i.p.; every 24 h for six days) prevented the development of hypertension, vascular dysfunction, and oxidative stress. L-NAME abolished NaHS-induced effects.Furthermore, NaHS treatment restored H2S-synthesizing enzymes and eNOS phosphorylation with no effect on body weight, sensorimotor impairments, or brain water content. SignificanceTaken together, these results demonstrate that H2S prevents TBI-induced hypertension by restoring vascular function and modulating ROS levels, H2S-synthesizing enzymes expression, and eNOS phosphorylation.