In order to begin separating the roles of membrane protein structure a
nd membrane protein milieu in anaesthetic interactions a new planar li
pid bilayer technology is being used. Membrane proteins such as sodium
channels from diverse tissue sources are inserted into identical lipi
d and aqueous environments where they can be examined and compared ele
ctrophysiologically in great detail. The results obtained with pentoba
rbitone suggest that some anaesthetic interactions may be general and
conserved, while other anaesthetic interactions may depend on the part
icular sodium channel isoform. Furthermore, the alteration of the memb
rane lipid composition can modulate anaesthetic effects. These results
suggest that some cells may be more sensitive to anaesthetics than si
milar cells in other tissues which express a different sodium channel
type or a different membrane environment. Therefore, caution must be e
xercised when generalizing findings concerning anaesthetic interaction
s with channels from one tissue or cell type to all other channel isof
orms.