EFFECT OF HIGH ETHANOL INTAKE ON VASCULAR REACTIVITY TO SEROTONIN, VASOPRESSIN AND ACETYLCHOLINE IN NORMOTENSIVE RATS

Chronic ethanol administration causes hypertension and alterations of vascular reactivity in rats. In several models of hypertension, altera tions of vascular reactivity are believed to be secondary to the susta ined increase in blood pressure. The present study investigated the ef fects of serotonin (5-hydroxytryptamine [5-HT]), vasopressin and acety lcholine (ACh) in the isolated perfused mesenteric arteries from Wista r rats submitted to an 8-week course of chronic ethanol intake (8 g/kg .day). No significant differences were observed in the dose - response curves with regard to: pressor effect of 0.04 - 10.0 nmole 5-HT; rela xant effect of 0.05 - 50.0 nmole ACh; or the pressor effects of two 1. 5-nmole doses of vasopressin between control rats and ethanol-fed rats . These results suggest that modifications in arterial reactivity to e ndogenous vasoactive substances (observed in other studies involving m ore prolonged ethanol treatment in rats) may be, in part, secondary to the increase in blood pressure.