Nitric Oxide Scavenging by Hydroxocobalamin May Account for Its Hemodynamic Profile

摘要

Background. Antidotal doses of hydroxocobalamin are associated with transient increases in blood pressure in some animals and humans. These studies in anesthetized rabbits were undertaken to explore the possible mechanisms underlying the hemodynamic effects of hydroxocobalamin by investigating 1) possible hemodynamic effects of cyanocobalamin, which is formed on a molar-to-molar basis when hydroxocobalamin binds cyanide, and 2) the interference of hydroxocobalamin with the endothelial nitric oxide system. Methods. Study 1 investigated the hemodynamic effects of cyanocobalamin. This study included two treatment arms: 1) cyanocobalamin (75 mg/kg, IV) followed by saline (n = 7) and 2) saline followed by cyanocobalamin (n = 7). Study 2 assessed the hemodynamic effects of hydroxocobalamin (75 mg/kg, IV) in the presence and absence of the nitric oxide synthase inhibitor L-A