2,6-DIISOPROPYLPHENOL, A GENERAL ANESTHETIC, INHIBITS GLUTAMATE ACTION ON RAT SYNAPTOSOMES

2,6-diisopropylphenol (propofol), a general intravenous anesthetic, inhibits the glutamate-dependent Ca2+, entry in rat synaptosomes with an approximate IC50 of 3.0 x 10(-5) M. Propofol, at concentrations above 10(-6)M, also inhibits the ATP-dependent uptake of glutamate in the presence of Ca2+, with an approximate IC50 of 3.5 x 10(-5)M, while it only has a slight inhibitory effect on the release of glutamate. The ouabain-insensitive synaptosomal ATPase is strongly inhibited by propofol, with an IC50 of about 2.5 x 10(-6)M, at concentrations which do not affect the luciferase system.