Do general anaesthetics perturb lipid membranes? The role of cholesterol.
The effect of enflurane and methoxyflurane on the permeability of liposomes to H+ was rested. Liposomes were prepared with phospholipids alone or as mixtures of cholesterol and phospholipids having the ratios of 1:2 or 1:1. Both anaesthetic drugs facilitated the release of H+ from pure phospholipid liposomes and from those with a 1:2 ratio. The facilitated release of H+ was prevented by the presence of high concentrations of cholesterol. As the cholesterol:phospholipid ratio in synaptic vesicles is of the order 1:2, it is expected that their permeability might be affected by volatile anaesthetics, leading to a modification of synaptic transmission.
D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D002784:Cholesterol / Q000378:metabolism*; D004737:Enflurane / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008081:Liposomes / Q000378:metabolism*; D008733:Methoxyflurane / Q000494:pharmacology*; D008954:Models, Biological; D010743:Phospholipids / Q000378:metabolism*; D013572:Synaptic Vesicles / Q000187:drug effects* / Q000378:metabolism
D008081:Liposomes; D010743:Phospholipids; D008733:Methoxyflurane; D004737:Enflurane; D002784:Cholesterol