DIFFERENTIAL EFFECTS OF ETHANOL AND MANNITOL ON CONTRACTION OF ARTERIAL SMOOTH-MUSCLE

Abstract

The present work, using isolated rat aortic strips, indicates that ethanol can inhibit development of spontaneous mechanical activity, induce contractions which are not inhibited by specific amine antagonists and potentiate or inhibit contractions induced by epinephrine and vasopressin. Ethanol also can attenuate contractions induced by K+ and can inhibit Ca++-induced contractions of K+-depolarized rat aortic strips. Experiments with a nonpenetrating substance, mannitol, suggest that the effects of ethanol are probably not solely a reflection of hyperosmolarity. Ethanol may induce hyper- or hypoexcitability of aortic smooth muscle by affecting movement and/or translocation of Ca++.