Drug-biomolecule interactions: spin-probe study of effects of anesthetics on membrane lipids.

The electron spin resonance spectra of probes were used to study the organization and motion of molecules in hydrated stacked bilayer or liposome model membrane systems. The same steroid structures required for reduction of membrane permeability were required to produce well-ordered films of brain lipid. Alcohols and anesthetic agents influence the structure of model membranes, with their order of efficacy paralleling their pharmacological effectiveness. Spin probes were also used to demonstrate effects of calcium and local anesthetics on the rate of penetration of ascorbate into lipid bilayers.