A spin trap study on anaerobic dehalogenation of halothane by a reconstituted liver microsomal cytochrome P-450 enzyme system.
In the presence of a spin trapping reagent, N-tert-butyl-alpha-phenylnitrone, anaerobic incubation of halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) with a reconstituted cytochrome P-450 enzyme system of rabbit liver microsomes exhibited an electron spin resonance spectrum containing signals of a nitroxide radical, and all components of the reconstituted system were necessary to produce the nitroxide radical. Formation of 2-chloro-1,1,1-trifluoroethane, the product of anaerobic dehalogenation of halothane by the reconstituted system, was inhibited by N-tert-butyl-alpha-phenylnitrone. These results indicate that a radical intermediate of halothane is produced during the anaerobic dehalogenation reaction, and that the radical is trapped by N-tert-butyl-alpha-phenylnitrone to form a N-tert-butyl-alpha-phenylnitrone radical adduct.
D000693:Anaerobiosis; D000818:Animals; D003497:Cyclic N-Oxides; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D006221:Halothane / Q000378:metabolism*; D007202:Indicators and Reagents; D008862:Microsomes, Liver / Q000201:enzymology*; D009589:Nitrogen Oxides; D011817:Rabbits
D003497:Cyclic N-Oxides; D005609:Free Radicals; D007202:Indicators and Reagents; D009589:Nitrogen Oxides; C029217:phenyl-N-tert-butylnitrone; D003577:Cytochrome P-450 Enzyme System; D006221:Halothane