Alcohol and Alcoholism Advance Access published online on May 21, 2008
Alcohol and Alcoholism, doi:10.1093/alcalc/agn042
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Alcohol Induces Relaxation of Rat Thoracic Aorta and Mesenteric Arterial Bed
Department of Physiology, Zhejiang University School of Medicine, 388 Yuhangtang Road, Hangzhou 310058, China
* Corresponding author: Department of Physiology, Zhejiang University School of Medicine, 388 Yuhangtang Road, Hangzhou 310058, China. Tel:/Fax: +86-571-88208252; E-mail: xiaqiang{at}zju.edu.cn
Received 12 December 2007; first review notified 29 January 2008; in revised form 13 April 2008; accepted 25 April 2008
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Abstract |
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Aims: The aim of this study was to investigate the effect of alcohol on rat artery and its underlying mechanism. Methods: The tension of isolated Sprague-Dawley rat thoracic aortic rings and the pressure of rat mesenteric arterial beds perfused with different concentrations of alcohol (0.1–7.0
) were measured. Results: At resting tensions, alcohol caused a concentration-dependent relaxation on endothelium-denuded aortic rings precontracted with KCl (6x10–2 mol/L) or phenylephrine (PE, 10–6 mol/L), and this effect was most evident on rings at a resting tension of 3 g. Alcohol induced much less vasodilation on endothelium-intact rings. Alcohol inhibited the CaCl2-induced contraction of endothelium-denuded aortic rings precontracted with KCl or PE. Incubation of rings with dantrolene (5x10–5 mol/L), a ryanodine receptor blocker, or 2-aminoethyl diphenylborinate (7.5x10–5 mol/L), an IP3 receptor blocker, attenuated the vasodilating effect of alcohol on rings precontracted with PE. Alcohol also concentration-dependently relaxed rat mesenteric arterial beds precontracted with KCl (6x10–2 mol/L) or PE (10–5 mol/L), which was more potent on endothelium-denuded than on endothelium-intact beds. Conclusions: Alcohol has a vasodilating effect on rat artery depending on the resting tension. Both extracellular and intracellular Ca2+ mobilization of vascular smooth muscle cells are involved in the vascular effect of alcohol.