Purpose: Activation of the renin-angiotensin system leads to an increase in oxidative stress. We investigated erythrocyte antioxidant enzymes, glutathione peroxidase, glutathione reductase and glutathione-S-transferase activities and as an index for oxidative stress plasma malondialdehyde levels and the effect of endovascular treatment on these parameters in renovascular hypertensive patients.

Methods: In 28 patients with unilateral renal artery stenosis, plasma malondialdehyde; erythrocyte glutathione peroxidase, glutathione reductase and glutathione-S-transferase activities were investigated at entry and after 24 hours of endovascular treatment and compared with controls.

Results: Malondialdehyde concentrations were higher in patients than controls and decreased 24 hours after the intervention. Erythrocyte glutathione peroxidase, glutathione reductase and glutathione-S-transferase activities were significantly higher in patients than controls. However, their activities did not differ after the intervention. After the treatment blood pressures decreased.

Conclusion: Oxidative stress and glutathione related enzyme activities are increased in renovascular hypertension. The increase in the enzyme activities could be attributed to a defence mechanism against oxidative stress. Endovascular treatment decrease the oxidative stress without affecting the glutathione peroxidase, glutathione reductase and glutathione-S-transferase enzyme activities.