Acute Ethanol Intake Induces NAD(P)H Oxidase Activation and Rhoa Translocation in Resistance Arteries

Abstract

BackgroundThe mechanism underlying the vascular dysfunction induced by ethanol is not totally understood. Identification of biochemical/molecular mechanisms that could explain such effects is warranted.ObjectiveTo investigate whether acute ethanol intake activates the vascular RhoA/Rho kinase pathway in resistance arteries and the role of NAD(P)H oxidase-derived reactive oxygen species (ROS) on such response. We also evaluated the requirement of p47phox translocation for ethanol-induced NAD(P)H oxidase activation.MethodsMale Wistar rats were orally treated with ethanol (1g/kg, p.o. gavage) or water (control). Some rats were treated with vitamin C (250 mg/kg, p.o. gavage, 5 days) before administration of water or ethanol. The mesenteric arterial bed (MAB) was collected 30 min after ethanol administration.ResultsVitamin C prevented ethanol-induced increase in superoxide anion (O2-) generation and lipoperoxidation in the MAB. Catalase and superoxide dismutase activities and the reduced glutathione, nitrate and hydrogen peroxide (H2O2) levels were not affected by ethanol. Vitamin C and 4-methylpyrazole prevented the increase on O2- generation induced by ethanol in cultured MAB vascular smooth muscle cells. Ethanol had no effect on phosphorylation levels of protein kinase B (Akt) and eNOS (Ser1177 or Thr495 residues) or MAB vascular reactivity. Vitamin C prevented ethanol-induced increase in the membrane: cytosol fraction ratio of p47phox and RhoA expression in the rat MAB.ConclusionAcute ethanol intake induces activation of the RhoA/Rho kinase pathway by a mechanism that involves ROS generation. In resistance arteries, ethanol activates NAD(P)H oxidase by inducing p47phox translocation by a redox-sensitive mechanism.

Cardiovascular Consequences of Binge Drinking: An Integrative Review with Implications for Advocacy, Policy, and Research

“…Pretreatment of animals with Losartan, an angiotensin receptor blocker, prevented binge‐induced increases in oxidative stress markers, as well as binge‐induced translocation of p47 phox and NADPH oxidase activation, suggesting a role for angiotensin II in mediating binge‐induced oxidative stress in aortic tissue (Yogi et al., ). In another investigation, using the same binge drinking model, those investigators found that some, but not all, of the aforementioned oxidative stress markers were changed in mesenteric resistance vessels (Gonzaga et al., ; Simplicio et al., ). For example, increases were found in TBARS and superoxide anion and NADPH oxidase expression (i.e., increase in the membrane/cytosol fraction ratio of p47 phox ), while no changes were found in hydrogen peroxide or glutathione levels and super oxide dismutase or catalase activity (Simplicio et al., ) or angiotensin I or II in mesenteric tissues (Gonzaga et al., ).…”

“…In that same study, increases in aortic tissue proinflammatory markers, such as cyclooxygenase‐2, tumor necrosis factor‐α, and monocyte chemoattractant protein‐1, were found along with increases in angiotensin II in aortic tissue (Husain, ). Similarly, in a series of investigations designed to examine the 1‐time effect of a binge dose of EtOH (1 g/kg via gavage, peak BAC levels 114 mg/dl within 30 minutes of gavage) in Wistar rats, Tirapelli and colleagues found evidence of increases in several oxidative markers (Gonzaga et al., ; Simplicio et al., ; Yogi et al., ). In the aforementioned model, increased plasma levels of thiobarbituric acid‐reacting substances (TBARS) and increased aortic endothelial and smooth muscle cell superoxide anion levels were found, along with increased membrane‐to‐cytosol fraction expression of the p47 phox subunit of NADPH oxidase (Yogi et al., ).…”

“…Repeated, chronic binge drinking is associated with a robust oxidative response, which correlates to both increases in BP and angiotensin II levels (Husain, ). Findings from other studies indicate that some of the oxidative stress changes can be prevented by pretreatment with agents that block the effects of angiotensin II (Yogi et al., ) or antioxidant/scavenging agents, such as vitamin C (Simplicio et al., ).…”

“…Binge drinking was defined by standard drinks in 2 hours (more than 5 in men, 4 in women) (Goslawski et al., ). Findings from studies using isolated endothelial‐intact vascular preparations (e.g., aortic or resistance arteriole ring segments) isolated from animals exposed to a 1‐time and repeated binge drinking episodes consistently report reduced acetylcholine‐induced vasodilation, suggesting endothelial dysfunction (Husain, ; Simplicio et al., ; Yogi et al., ).…”

He Role of Nadph Oxidases in the Formation of Alcohol-Induced Oxidative Stress

“…Показательно, что аскорбиновая кислота предупреждала этанол-индуцированную генерацию супероксида [21]. Также в экспериментах с оценкой воздействия интраперитонеального введения 25 %-ного раствора этанола мышам линии C57D/6J показано, что основные изменения экспрессии NOX1 происходят в нервной ткани: увеличен уровень мРНК NOX1, DUOX2 [22].…”