Hydroxylation of 5,5-diphenylhydantoin (phenytoin) by dog liver microsomes.
Chang and Glazko in 1972 had reported failure to demonstrate any production from 5-5-diphenylhydantoin (phenytoin, DPH) by dog liver microsomes of either 5-(m-hydroxyphenyl-5-phenylhydantoin (m-HPPH) or 5-(P-hydroxyphenyl-5-phenylhydantoin (p-HPPH), metabolites of DPH  produced by the dog in vivo. We have incubated DPH with 9,000 X g supermatants of dog liver homogenates and with suspensions of separated microsomes with added NADPH generating system, Mg(2+), and nicotinamide and have demonstrated the production of both m-HPPH and p-HPPH. Both metabolities were detected by thin-layer chromatography of extracts of the incubation mixtures. Detection and roughly quantitative measurement of m-HPPH were also accomplished with gas chromatography.
D000818:Animals; D002855:Chromatography, Thin Layer; D004285:Dogs; D005260:Female; D006900:Hydroxylation; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D010672:Phenytoin / Q000378:metabolism*
D009249:NADP; D010672:Phenytoin