GENETIC-DIFFERENCES AFFECTING THE POTENCY OF STEREOISOMERS OF HALOTHANE

The mechanism of action of volatile anesthetics is the subject of some debate. Much of the controversy has centered on whether the site of s uch actions is purely lipid in nature or may contain a protein target. This report studies the interaction of stereoisomers of halothane on the wild type and on a variety of genetic mutants of Caenorhabditis el egans. The mutants studied have previously been shown to have altered sensitivities to volatile anesthetics. In one mutant, fc34, (R)-haloth ane [the (+) isomer] was 3 times more potent than its S (-) isomer. Ot her mutants and wild-type animals displayed more modest differences in sensitivity to the enantiomers. The results indicate that a genetic p athway exists in C. elegans controlling sensitivity to halothane and t hat both lipid and protein targets may mediate halothane's effects.