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Troiano J.A.,Programa de Pos Graduacao Multicentrico em Ciencias Fisiologicas | Troiano J.A.,Sao Paulo State University | Potje S.R.,Programa de Pos Graduacao Multicentrico em Ciencias Fisiologicas | Potje S.R.,Sao Paulo State University | And 14 more authors.
Life Sciences | Year: 2016

Aims We determined whether decreased reactive oxygen species (ROS) production in the aorta of pregnant spontaneously hypertensive rats (SHR) resulted in increased nitric oxide (NO) bioavailability and hyporeactivity to phenylephrine (PE). Main methods Systemic and aortic oxidative stress were measured in pregnant and non-pregnant Wistar rats and SHR. Furthermore, the hypotensive effects of apocynin (30 mg/kg) and Tempol (30 mg/kg) were analyzed. Intact aortic rings of pregnant and non-pregnant rats were stimulated with PE in the absence of or after incubation (30 min) with apocynin (100 μmol/L). The effect of apocynin on the concentrations of NO and ROS were measured in aortic endothelial cells (AEC) using DAF-2DA (10 mmol/L) and DHE (2.5 mmol/L), respectively. Western blotting was performed to analyze eNOS, NOX1, NOX2, NOX4 and SOD expression. ROS production was analyzed by the lucigenin chemiluminescence method. Key findings Aortic oxidative stress and ROS concentration in AEC were reduced in pregnant Wistar rats and SHR, when compared to non-pregnant rats. ROS production and NOX1, NOX2 and NOX4 expression in the aortas were decreased in pregnant SHR, but not in pregnant Wistar rats. Increased eNOS expression in aortas and NO concentration in AEC were observed in pregnant Wistar rats and SHR. Apocynin reduced PE-induced vasoconstriction in the aortas of non-pregnant Wistar rats and SHR, and pregnant Wistar rats, but not in the aortas of pregnant SHR. Significance Taken together, these results suggest that ROS production was decreased in the aortas of pregnant SHR and could contribute to higher NO bioavailability and hyporeactivity to PE in the aortas of pregnant SHR. © 2015 Published by Elsevier Inc. Source


Zancheta D.,Programa de Pos Graduacao Multicentrico em Ciencias Fisiologicas | Zancheta D.,Sao Paulo State University | Troiano J.A.,Programa de Pos Graduacao Multicentrico em Ciencias Fisiologicas | Troiano J.A.,Sao Paulo State University | And 8 more authors.
Life Sciences | Year: 2015

Aim This study aimed to evaluate the effects of Wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), on aortic hyporeactivity to Phenylephrine (Phe) and nitric oxide bioavailability associated with pregnancy in hypertensive rats. Main methods The intact aortic rings of pregnant and non-pregnant Wistar or spontaneously hypertensive rats (SHRs) were stimulated with Phe (1 nmol/L to 10 mmol/L) before and after incubation with Wortmannin (10 nmol/L, 30 min). Western blot experiments analyzed the expression of phosphorylated PI3K [p85-PI3K], Akt [p-Akt (Ser 473)] and eNOS [p-eNOS (Ser 1177)] in aorta homogenates of pregnant and non-pregnant Wistar rats or SHRs. The effect of Wortmannin (10 nmol/L) on the cytosolic concentrations of nitric oxide (NO; measured using 4,5-diaminofluorescein diacetate [DAF-2DA], 10 mmol/L), Ca2 + (using Fluo 3-AM, 5 μmol/L) and reactive oxygen species (ROS; using dihydroethidium [DHE], 2.5 mmol/L) were measured fluorimetrically in freshly isolated endothelial cells. Key findings Wortmannin increases the reactivity of the aorta to Phe and decreases NO concentrations in the aortic endothelial cells of pregnant Wistar rats and SHR. Significance The PI3/AKT/endothelial nitric oxide synthase (eNOS) pathway contributes to aortic hyporeactivity to Phenylephrine associated with pregnancy in normo- and hypertensive rats. © 2014 Elsevier Inc. All rights reserved. Source

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