Short-term use of telmisartan attenuates oxidation and improves Prdx2 expression more than antioxidant β-blockers in the cardiovascular systems of spontaneously hypertensive rats

Abstract

Reactive oxygen species (ROS) and antioxidant enzymes are required to maintain homeostasis. The loss of this balance can cause excessive ROS production and damage to the cardiovascular tissues. Angiotensin II receptor blockers (ARBs) and β-blockers with antioxidant effects may inhibit ROS in the cardiovascular system. In this study, we directly compared the effects of ARBs and β-blockers with antioxidant properties on cardiovascular protection and the regulation of endothelial progenitor cell (EPC) numbers in the setting of oxidative stress in hypertensive rats. To compare the effects of the drugs, animals were divided into the following groups: Wistar-Kyoto rats (WKY), untreated spontaneously hypertensive rats (SHR) and SHR treated with tempol (TEMP, 5 mg kg-1 per day), trichlorothiazide (TCTZ, 1.6 mg kg-1 per day), atenolol (25 mg kg-1 per day), nebivolol (NEBL, 5 mg kg-1 per day), carvedilol (CVDL, 30 mg kg-1 per day) or telmisartan (TERT, 5 mg kg-1 per day). Following 2 weeks of treatment, blood pressures (BPs) and aortic wall thicknesses were similarly reduced in each antihypertensive drug-treated group. Superoxide anion and malondialdehyde levels were significantly reduced following treatment with NEBL, CVDL and TERT. Additionally, the expression levels of NADPH oxidase subunits were also reduced in the TERT-, CVDL-and NEBL-treated groups. Furthermore, these drugs improved both EPC numbers and the expression levels of peroxiredoxin 2 (Prdx2), an antioxidant enzyme, in the heart and kidneys but not the aorta. Cardiac Prdx2 expression, in particular, was markedly improved by TERT, NEBL and CVDL treatment, and renal Prdx2 expression was enhanced by TEMP. Our data indicate that short-term treatment with TERT may have more beneficial effects on cardiovascular protection, EPC number improvements and Prdx2 expression compared with CVDL and NEBL. In conclusion, TERT may positively modulate the balance between oxidative stress and antioxidant properties and demonstrate capabilities beyond its BP-lowering effects.