RESUMO
AIM To study in vitro stereoselective metabolism of mandelic acid (MA) in 3 kinds of laboratory animal tissue fractions and observe the differences of MA biotransformation. METHODS MA enantiomers were incubated with the tissue fractions from rats, mice and rabbits. The phenylglyoxylic acid (PGA) concentrations in incubation mixture were determined by high-performance liquid chromatography. Coenzymes and inhibitors were co-incubated with MA to investigate their effects on MA metabolism. RESULTS Only S-MA showed a unique metabolism in liver and kidneys S9 fractions of rats. No inhibition of the enzyme activity was observed by addition of ethanol or 4-methyl pyrazole. NADPH caused a remarkable increase in S-MA metabolism. CONCLUSION Nonmicrosomal enzymes in kidneys and liver except alcohol dehydrogenase are responsible for the stereoselective metabolism of MA in rats. The MA biotransformation is significantly different between rats and mice or rabbits.