A model for the interaction of anesthetics with the phospholipid membrane headgroup-interface region.

A previous model for lipid-anesthetic interaction is modified to account for anesthetics which bind to the headgroup-interface region of the bilayer rather than the acyl chain region. The new models account for anesthetic-induced changes in membrane phase transition temperature and permeability as well as the previous model, while still accounting for pressure reversal of anesthesia. In addition, the new models account for a 'saturation' of the effect of increasing concentrations of anesthetic on the membrane phase transition temperature, in agreement with experiment and in contrast to our previous model.