Chronic ethanol consumption alters vascular smooth muscle responses in rats

1. The effect of chronic ethanol (10%) consumption for 5 months on vascular smooth muscle (VSM) using aortic rings of both sexes of Sprague-Dawley rats was studied. 2. Chronic ethanol consumption increased the sensitivity of VSM to noradrenaline (NA) in both male and female ethanol-treated rats. 3. There was no significant difference in the contractile response of male and female ethanol-treated rats to NA. Hence, the enhancement of vascular contractility to the agonist due to chronic ethanol consumption is independent of gender. 4. Vascular relaxation induced by acetylcholine showed similar responses in all experimental groups. Thus, chronic ethanol consumption seems to have no significant effect on the production of endothelium-dependent relaxing factor. 5. However, the VSM sensitivity to potassium chloride was increased in female ethanol-treated rats, whereas male ethanol-treated rats had similar responses as controls. 6. The results suggest that the effect of chronic ethanol consumption on VSM varies with gender. Impairment of VSM in male ethanol-treated rats is due partly to changes in the receptor-operated channel, whereas in females it is due to changes in both receptor- and potential-operated channels.