Preventive effects of exercise training on dexamethasone‐induced hypertension, oxidative stress and peripheral insulin resistance

Abstract

This study investigated whether exercise training (T) could prevent the insulin resistance, oxidative stress and hypertension induced by dexamethasone (Dexa) treatment. Rats underwent a T period where they were either submitted to a running protocol (8weeks) or kept sedentary. After this T period, the animals underwent a Dexa treatment (1mg/kg/day, i.p., 10days), concomitant with training. An ipGTT was performed at the end of the experimental period and the area under the glucose curve (AUC) was calculated. Arterial pressure (AP) was measured. Reduced/oxidized glutathione ratio (GSH/GSSG) and lipid peroxidation were also determined in the skeletal muscle. Western blot analysis was performed to identify PKCα protein expression in the tibialis anterior (TA) muscle. Dexa increased AP (23 mmHg) and T attenuated this increase by 11%. Dexa decreased the GSH/GSSG ratio by 44% and increased the lipid peroxidation by 55% in sedentary groups, and T blocked these alterations. Dexa reduced the PKC‐α protein expression by 45%, which was prevented by T. Accordingly, T attenuated the increases in the AUC, whose values were 39% higher in sedentary ones. Therefore T is effective in regulating physiological antioxidant systems and glucose uptake, which could contribute to prevent hypertension and insulin resistance induced by Dexa.