Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: chris on 25/09/2013 19:04:48

Title: How do general anaesthetics work?
Post by: chris on 25/09/2013 19:04:48

How do general anaesthetics work? Do we actually know? I've heard various claims about altering ion channel function etc, but then xenon is also a good GA isn't it? So what's the mechanism?

Title: Re: How do general anaesthetics work?
Post by: dlorde on 25/09/2013 23:10:36

Apparently xenon also interacts with various receptors and ion channels (http://en.wikipedia.org/wiki/Xenon#Anesthesia); not that noble then - who knew?

Title: Re: How do general anaesthetics work?
Post by: chiralSPO on 29/09/2013 20:21:01

I have heard that the effect is due to dissolution of the nonpolar molecules in cell membranes, causing slight swelling, and modifying the sensitivity and activity of all surface-bound proteins. Someone told me about a study where mice were anesthetized and then revitalized in a hyperbaric chamber, pressurized with helium (which doesn't dissolve well in the membranes). The mice would wake up when the pressure was increased above a certain level, and then fall into unconsciousness again when the pressure was released. This is why very deep-sea divers use He instead of N2 (which does dissolve in the membranes at elevated pressures, causing nitrogen narcosis).

Clearly there are other mechanisms available for molecules which bind to particular targets in the body, but for those which have no obvious binding site, this general swelling could be the major pathway.