Correlation of general anesthetic potency with solubility in membranes

Recently (Franks, N.P. and Lieb, W.R. (1978) Nature 274, 339-342) it has been claimed that the traditional correlation between anesthetic potency and vegetable oil solubility breaks down when the alkanols are compared to other volatile anesthetics. Lately, however, new information on the partitioning of anesthetics into lipid bilayers has become available. In this report the potency of twenty-one structurally diverse anesthetic agents is shown to correlate well with their ability to partition into phosphatidylcholine bilayers. Thus the original Meyer-Overton oil solubility hypothesis accommodates a wider range of anesthetics, including alkanols, volatile and gaseous agents, and barbiturates, when lipid bilayer solubility is substituted for oil solubility.