title: Alcohol induces relaxation of rat thoracic aorta and mesenteric arterial bed.
abstract: OBJECTIVE
  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 per thousand) were measured.
  
  
  RESULTS
  At resting tensions, alcohol caused a concentration-dependent relaxation on endothelium-denuded aortic rings precontracted with KCl (6 x 10(-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 CaCl(2)-induced contraction of endothelium-denuded aortic rings precontracted with KCl or PE. Incubation of rings with dantrolene (5 x 10(-5) mol/L), a ryanodine receptor blocker, or 2-aminoethyl diphenylborinate (7.5 x 10(-5) mol/L), an IP(3) 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 (6 x 10(-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 Ca(2+) mobilization of vascular smooth muscle cells are involved in the vascular effect of alcohol.
authors.affiliation: Department of Physiology, Zhejiang University School of Medicine, 388 Yuhangtang Road, Hangzhou 310058, China. xiaqiang@zju.edu.cn
authors.forename: Xiao-Chen
authors.initials: XC
authors.lastname: Ru
authors.forename: Ling-Bo
authors.initials: LB
authors.lastname: Qian
authors.forename: Qin
authors.initials: Q
authors.lastname: Gao
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Li
authors.forename: Iain C
authors.initials: IC
authors.lastname: Bruce
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xia
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects*; D001158:Arteries / Q000187:drug effects*; D000431:Ethanol / Q000494:pharmacology*; D008297:Male; D008643:Mesentery / Q000098:blood supply* / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D000431:Ethanol