Inhibition of human 5-HT3A and 5-HT3AB receptors by etomidate, propofol and pentobarbital

The actions of intravenous anaesthetics on 5-HT3AB receptors have not been studied. Using oocyte electrophysiology, the effects of etomidate, propofol, and pentobarbital on human 5-HT3A and 5-HT3AB receptors were studied and compared. Inhibition of peak currents by all three compounds in both receptor subtypes was anaesthetic concentration-dependant and non-competitive. Because the half-maximal inhibitory concentrations for etomidate, propofol and pentobarbital in 5-HT3A and 5-HT3AB receptors were all above their respective anaesthetic concentrations, the results of our study suggest that neither 5-HT3 receptor subtype contributes to the anaesthetic actions of etomidate, propofol or pentobarbital.