Effects of Calcitonin Gene-Related Peptide on Hemodynamic Responses, Catecholamine Release, and Carbohydrate Metabolism during Sevoflurane Anesthesia

Abstract

Calcitonin gene-related peptide (CGRP) induces vasodilation, hypotension, and tachycardia. Tachycardia induced by CGRP may be due to sympathetic activation. The volatile anesthetic sevoflurane attenuates arterial baroreflexes. We examined the hemodynamic, endocrine, and metabolic effects of CGRP infusion (4μg·kg-1) in dogs anesthetized with sevoflurane. Hemodynamic variables, plasma catecholamine, glucose and lactic acid were measured before, during, and after CGRP infusion. Anesthesia consisted of induction with pentobarbital, followed by 2.4% sevoflurane in oxygen. The decrease in mean arterial pressure induced by CGRP was due to a reduction in systemic vascular resistance associated with an increase in cardiac index, but was not accompanied by any change in heart rate. Mean pulmonary artery and pulmonary capillary wedge pressures remained unchanged during infusion but mean pulmonary artery pressure increased after infusion. Plasma norepinephrine concentrations increased, but epinephrine levels did not increase during infusion. Plasma glucose concentrations increased only during infusion, but plasma lactic acid concentrations increased throughout the observation perod. In conclusion, the current study demonstrated that the suppression in CGRP-induced tachycardia might be due to catecholamines resulting from sevoflurane-induced sympathetic suppression. These findings suggested that CGRP may be a useful vasodilator agent during sevoflurane anesthesia.