Abstract
The in vitro metabolism of ethylhexabital (EHB) was examined by incubating a rat liver slice with ethylhexabital in a Krebs-Ringer phosphate buffer containing 0.2% glucose, and the formation of 3-keto-EHB (5-(3′-oxo-1′-cyclohexen-1′-yl)-5-ethylbarbituric acid), a metabolite in the case of in vivo metabolism, was identified by paper chromatography, and the amount formed and the amount of unchanged EHB remaining were determined at the same time by ultraviolet spectrophotometry. The amount of 3-keto-EHB formed reaches the maximum by incubation in pH 7.4 at 38° for 3 hours, with 750γ EHB for 500mg. of the liver slices. The action of liver brei is much weaker than its slice, while the action of the liver homogenate, kidney slice, and brain brei was much weaker but clearly indicated the formation of 3-keto-EHB. Pretreatment at 100° for 10 minutes or at 60° for 1 hour, or the addition of 0.02M potassium cyanide effect entirely no formation of 3-keto-EHB.
