Abstract
The purpose of this investigation is to correlate between trimethadione (TMO) metabolism and hepatic microsomal drug-oxidizing activities in different animal species (mouse, hamster, rat and rabbit). A good correlation was obtained between the plasma concentration ratio of 5, 5-dimethyl-2, 4-oxazolidinedione (DMO) to TMO and relative activities of aminopyrine (γ=0.999 at 1 h, p<0.01;γ=0.994 at 2 h, p<0.01) and TMO (γ=0.988 at 1 h, p<0.02;γ=0.975 at 2 h, p<0.05) N-demethylase, and aniline (γ=0.993 at 1 h, p<0.01;γ=0.979 at 2 h, p<0.01) hydroxylase. These results indicate that the values of plasma DMO/TMO ratio determined at an appropriate time period following its administration would be reflecting the degree of hepatic drug-oxidizing capacity in various experimental animal species. These findings thus suggest that in vivo TMO metabolism would be a useful drug for predicting hepatic drug-oxidizing capacity in humans.
