Isoflurane-, Halothane- and Agonist-Evoked Responses in Pig Coronary Arteries and Vascular Smooth Muscle Cells

Abstract

The actions of volatile anesthetics are not restricted simply to depression of consciousness but extend beyond the nervous system to include the heart and circulation. In the circulation, isoflurane and halothane cause vasodilatation; although a part of this effect results simply from decreased nervous system activity, the anesthetics undoubtedly also have direct actions on blood vessels themselves. The nature and magnitude of the anesthetics’ vascular effects vary depending upon animal species, vascular bed and type of vessel. In the coronary circulation of intact pigs and in isolated coronary arteries removed from pig, dog and human hearts, isoflurane and halothane have both been shown to attenuate agonist-induced contractile responses.^1–4 The purpose of the current experiments has been to investigate the effects and mechanisms of action of volatile anesthetics in coronary arteries and in cultured vascular cells.