Renovascular hypertension in rats: Temporal antioxidant adaptation

Abstract

Renovascular hypertension is a form of secondary hypertension, and reactive oxygen species play an important role in the pathophysiology of hypertension. Here, we tried to evaluate temporal changes in lipid peroxidation and antioxidant enzymes activity, in the course of renovascular hypertension. To induce renovascular hypertension, adult male Wistar rats were submitted to Goldblatt 2K1C surgery or sham-operated (sham). The blood pressure was directly assessed after 7, 14, 21 and 28 days. Lipid peroxidation, superoxide dismutase, catalase, glutathione peroxidase (GPx), and glutathione-S-transferase activities were evaluated in heart and kidneys. Mean blood pressure (mmHg) was higher by 20, 14, 23 and 22% (<em>P</em> <0.05), respectively in hypertensive groups 7, 14, 21 and 28 days, than in the control groups (108±7 in 7 days, 101±4 in 14 days, 109±7 in 21 days and 104±7 in 28 days in sham group; and 130±12 in 7 days, 116±4 in 14 days, 135±16 in 21 days and 127±6 in 28 days in hypertensive group). Lipid peroxidation, superoxide dismutase, catalase and glutathione S-transferase showed no significant changes. The GPx activity (nmoles.min^-1/mg protein) was 47% higher in the hearts (90.12±17.63 in sham group and 132.53±12.43 in hypertensive group), 98% in right kidney (66.13±15.10 in sham group and 131.23±28.32 in hypertensive group), 98% in left kidney of the hypertensive group 7 days in relation to sham group 7 days (67.05±17.87 in sham group and 132.87±35.31 in hypertensive group, <em>P</em> <0.05). The main adaptive change promoted by hypertension includes an induction of GPx during hypertensive status development.