CONTROL OF CYANIDE ACTION: CYANOHYDRIN EQUILIBRIA IN VIVO AND IN VITRO

¹ From the Department of Pharmacology and Experimental Therapeutics, Johns Hopkins School of Medicine

The protective value of aldehydes and ketones against cyanide poisoning and the respiratory response to cyanohydrins are correlated with three physico-chemical properties of cyanohydrin equilibria. The protective value against cyanide poisoning is determined by two properties, varying inversely as the equilibrium constant and directly as the rate of cyanohydrin formation. Initial respiratory stimulation is also determined by two of these properties, varying directly as the equilibrium constant and directly as the rate of cyanohydrin dissociation on dilution. Certain cyanohydrins with very small equilibrium constants were found to produce prolonged stimulation of the respiration. Pyruvic acid cyanohydrin, with a larger equilibrium constant but very slow rate of dissociation on dilution, was found to be particularly effective as a respiratory stimulant.