Efeitos do exercício resistido sobre a atividade das enzimas acetilcolinesterase e Na+/K+ ATPase e estresse oxidativo na hipertensão induzida por L-NAME

Abstract

Hypertension (HT) is a disease that affects billions of people around the world, being a risk factor for numerous other cardiovascular diseases, and may even affect the brain through poor blood distribution. In experimental models, induced hypertension is by daily administration of L-NAME. Resistance training has increasingly appeared as an auxiliary alternative in the treatment of hypertension due to its antihypertensive, antioxidant and neuroprotective effects. Thus, the objective of this study was to evaluate the effect of 4 weeks of resistance exercise on enzymatic activities and oxidative stress parameters in the cerebral cortex of rats with L-NAME-induced hypertension. For this purpose, 40 rats were divided into four groups: Sedentary Control (Sed-Ctrl), Exercise Control (Ex-Ctrl), Sedentary L-NAME (Sed-L-NAME) and Exercise L-NAME (Ex-LNAME). The L-NAME dose used was 30mg / kg / day and began one week before the exercise protocol. After 48 hours of the last exercise session, the samples were collected for the evaluations of nitrite and nitrate levels (NOx), total reactive species of oxygen (tROS), carbonyl protein, reactive species of thiobarbituric acid (TBARS), total thiols content and the activity of glutathione’s peroxidase (GPx), redutase (GR) and stransferase (GST), acetilcolinesterase (AChE) and Na+/K+ ATPase. In this experiment, we saw an L-NAME-induced lower gain of weight, which was restored to normal levels by the exercise, in the last week. We found increased levels of tROS and thiols in Sed- L-NAME group, both reverted to standard in Ex-L-NAME group. The NOx content in the Sed-L-NAME group decreased and the exercise restored it in Ex-L-NAME group. An increased activity of GPx for the Sed-L-NAME group was observed and its reestablishment in the Ex-L-NAME group was seen. We also could see an increased activity in AChE and a reduction in Na+/K+ ATPase of Sed-L-NAME groups, but the resistance exercise protocol was not able to restore this parameters. The other measures –TBARS, protein carbonylation, GR and GST- did not present a significant difference. These results are expected to better understand the damage caused by hypertension in the central nervous system as well as the effects of this exercise protocol as a possible aid in the treatment of HT.