Molecular sites of general anaesthetic action on XXXX receptors.

@entity4313 @entity167 @entity7353 @entity934
Mechanisms of anaesthetics still remain unclear. However, various attempts have been made to elucidate the effects of anaesthetics at the molecular level. The nicotinic @entity934 receptor has proved to be a good model of membrane-bound ligand-gated ion channels. It is available in abundance from Torpedo electroplaques, thus enabling multiple experimental approaches. The receptor exists in different states: the resting state, the open state and the desensitized state, amongst others. For each of these states, effects of general anaesthetics at the receptor molecule have been shown. Displacement studies show barbiturates to bind to a site on the resting state of the nicotinic @entity934 receptor; cation flux studies suggest @entity7353 may also bind to the same, or a similar, site on the open state of the receptor when inhibiting its function. Long-chain @entity4313 inhibit the open receptor, perhaps by binding to such a site or sites. However, short-chain @entity4313 do not inhibit and do not share this long-chain @entity167 binding site; instead they nonspecifically enhance the agonist's apparent affinity. All the @entity4313 also cause desensitization by a non-specific mechanism possibly involving perturbation of the lipid bilayer. Thus, general anaesthetics exert both specific and non-specific actions on the @entity934 receptor.
