ABSTRACT
An associated theory of inhalation anaesthetic action is the ‘protein theory5. This theory proposes that the anaesthetics act by interacting directly with proteins within the cell membrane, most notably ion channels and receptor proteins. Experiments have shown that, at therapeutic concentrations, the anaesthetic agents are able to inhibit the actions of some receptors for excitatory transmitters and enhance the activity of some receptors for inhibitory transmitters. It is probable, however, that neither theory can fully explain the actions of all general anaesthetics, with some agents acting by dissolution into the lipid membrane, thereby disrupting membrane-bound protein function and some acting by direct interaction with the same membrane-bound proteins.
