PT  - JOURNAL ARTICLE
AU  - E Benoit
AU  - T Cresteil
AU  - J L Riviere
AU  - P Delatour
TI  - Specific and enantioselective sulfoxidation of an aryl-trifluoromethyl sulfide by rat liver cytochromes P-450.
DP  - 1992 Nov 01
TA  - Drug Metabolism and Disposition
PG  - 877--881
VI  - 20
IP  - 6
4099  - http://dmd.aspetjournals.org/content/20/6/877.short
4100  - http://dmd.aspetjournals.org/content/20/6/877.full
SO  - Drug Metab Dispos1992 Nov 01; 20
AB  - Evidence based on thermal stability and enzyme inhibition data suggests that the sulfoxidation of the drug toltrazuril by rat liver microsomes is catalyzed by different cytochromes P-450. Pretreatment of rats by different inducers--phenobarbital, 3-methylcholanthrene, dexamethasone, and triacetyloleandomycin--results in a 2.1-, 2.6-, 2.9-, and 1.8-fold increase, respectively, in the rate of sulfoxidation. The highest increase (8.4-fold) was observed after treatment of microsomes from triacetyloleandomycin-treated animals by potassium ferricyanide. Castration and aging also modify the sulfoxidase activity. The relative rate of formation of the two toltrazuril enantiomers [(A)- and (B)-sulfoxides] depends on the source of the microsomes, suggesting that different cytochromes P-450 have different stereoselectivities.