Antioxidant Treatment Reverts Increased Arterial Basal Tone and Oxidative Stress in Nephrectomized (56)‎ Hypertensive Rats

Abstract EN

Nonischemic 5/6 nephrectomized rat (NefR) is a model of chronic kidney disease.

However, little is known about vascular dysfunction and its relation with hypertension in NefR.

Aims.

To evaluate possible alterations of endothelial function, NO-bioavailability, and basal tone in aorta from NefR and the role of oxidative stress.

Sprague Dawley rats were divided into sham rats (SR), NefR, and NefR treated with tempol (NefR-T).

Mean arterial pressure (MAP) and renal function were determined.

In isolated aortic rings the following was measured: 1-endothelial function, 2-basal tone, 3-NO levels, 4-membrane potential (MP), and 5-oxidative stress.

NefR increased MAP (SR: 119 ± 4 mmHg; n=7; NefR: 169 ± 6; n=8; P<0.001).

Tempol did not modify MAP (NefR-T: 168 ± 10; n=6; P<0.001).

NefR showed endothelial dysfunction, increased basal tone and decreased NO levels (SR: 32 ± 2 nA; n=7, NefR: 10 ± 2; n=8; P<0.001).

In both in vitro and in vivo tempol improves basal tone, NO levels, and MP.

Oxidative stress in NefR was reverted in NefR-T.

We described, for the first time, that aorta from NefR presented increased basal tone related to endothelial dysfunction and decreased NO-bioavailability.

The fact that tempol improves NO-contents and basal tone, without decrease MAP, indicates that oxidative stress could be implicated early and independently to hypertension, in the vascular alterations.