title: Antioxidant treatment reverts increased arterial Basal tone and oxidative stress in nephrectomized (5/6) hypertensive rats.
abstract: 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.
authors.affiliation: Departamento de Fisiología, INSIBIO-Universidad Nacional de Tucumán, Balcarce 32, 4000 Tucumán, Argentina ; Department of Physiology and Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA.
authors.forename: Rodrigo O
authors.initials: RO
authors.lastname: Marañón
authors.forename: Claudio
authors.initials: C
authors.lastname: Joo Turoni
authors.forename: Maria Sofia
authors.initials: MS
authors.lastname: Karbiner
authors.forename: Nicolas
authors.initials: N
authors.lastname: Salas
authors.forename: Maria
authors.initials: M
authors.lastname: Peral de Bruno