Bldg 53, 101 City Drive South, Orange, CA 92868, USA. If the in ... agent. Positron emission tomography data from volunteers studied while unconscious during.
British Journal of Anaesthesia 86 (5): 618±26 (2001)
CLINICAL INVESTIGATIONS Correlating in vivo anaesthetic effects with ex vivo receptor density data supports a GABAergic mechanism of action for propofol, but not for iso¯urane² ³ M. T. Alkire1* and R. J. Haier2 1
Department of Anesthesiology and 2Department of Pediatrics, University of California-Irvine Medical Center, Orange, California
*Corresponding author: Department of Anesthesiology, University of California, Irvine Medical Center, Route 81A, Bldg 53, 101 City Drive South, Orange, CA 92868, USA If the in vivo effects of anaesthesia are mediated through a speci®c receptor system, then a relationship could exist between the regional changes in brain metabolism caused by a particular agent and the underlying regional distribution of the speci®c receptors affected by that agent. Positron emission tomography data from volunteers studied while unconscious during propofol (n=8) or iso¯urane (n=5) anaesthesia were used retrospectively to explore for evidence of relationships between regional anaesthetic effects on brain glucose metabolism and known (ex vivo) regional distribution patterns of human receptor binding sites. The regional metabolic reductions caused by propofol differed signi®cantly from those of iso¯urane. Propofol's reductions negatively correlated most signi®cantly with the regional distribution of [3H]diazepam and [3H]¯unitrazepam (benzodiazepine) binding site densities (r=±0.86, P
