Effect of ethanol consumption on blood pressure and rat mesenteric arterial bed, aorta and carotid responsiveness

This study investigates whether chronic ethanol consumption increases blood pressure and alters vascular reactivity in different tissues. Changes in reactivity to phenylephrine and acetylcholine were investigated in the aorta, carotid artery and mesenteric arterial bed (MAB) isolated from rats pretreated with ethanol for 2 or 6 weeks. Mild hypertension was observed in chronically ethanol‐treated rats, which was due to rises in both systolic and diastolic pressures. Chronic ethanol consumption increased the contractile response to phenylephrine of endothelium‐intact and denuded rat aortic rings from rats pretreated with ethanol for 2 or 6 weeks. Conversely, no differences were found in acetylcholine‐induced relaxation. Neither phenylephrine‐induced contraction nor acetylcholine‐induced relaxation were altered in the rat carotid. Six weeks' ethanol consumption enhanced the contractile response to phenylephrine of endothelium‐intact, but not denuded rat MAB. On the other hand, 2 weeks' ethanol consumption did not affect phenylephrine‐induced increase in perfusion pressure. Moreover, acetylcholine‐induced endothelium‐dependent relaxation in the MAB was reduced after treatment with ethanol for 6 weeks but not after 2 weeks. In conclusion, ethanol affects both blood pressure and vessel reactivity, but the effect on vascular reactivity may take longer to become apparent in MAB than in the aorta, and was not evident in the carotid. Moreover, we provide evidence that the effect of ethanol depends on the agonist and blood vessel studied.