[2-14C]caffeine metabolism in control and 3-methylcholanthrene induced rat liver microsomes by high pressure liquid chromatography.
Theobromine, theophylline, paraxanthine and 1,3,7-trimethyluric acid were identified as caffeine metabolites after incubation of [2-14C]caffeine with rat liver microsomes and separation by high-pressure liquid chromatography (HPLC). A 9-fold induction of caffeine metabolism was observed in 3-methylcholanthrene (MC)-induced microsomes and this induction ranged from 4 to 11 times for individual metabolites. Induction of aryl hydrocarbon hydroxylase (AHH) was about 5-fold, comparable to that of theophylline formation. Primary caffeine metabolism is an enzymic process catalyzed by the microsomal mixed-function oxidases.
D000818:Animals; D002110:Caffeine / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004790:Enzyme Induction; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology*; D008862:Microsomes, Liver / Q000201:enzymology*; D051381:Rats
D002110:Caffeine; D008748:Methylcholanthrene