EFFECTS OF STREPTOLYSIN-O, PICIBANIL (OK-432) AND INTERFERON ALPHA-2AON CYTOCHROME P-450-DEPENDENT MONOOXYGENASES AND ARYLAMINE N-ACETYLTRANSFERASE IN RAT-LIVER

Streptolysin O, a thiol-activated exotoxin from group A beta-haemolyti c streptococci, caused a dose-dependent depression of aniline hydroxyl ase, aminopyrine N-demethylase and ethylmorphine N-demethylase activit ies when added into the hepatic microsomal mixtures from male rats at concentrations 0.02 - 0.4 HU/mL in vitro. The activities of 7-ethoxyco umarin O-deethylase, 7-ethylresorufin O-deethylase and 7-pentylresoruf in O-depentylase were not altered with the used concentrations of the toxin. Specific antibody against haemolytic action of streptolysin O a dded to incubation mixtures in vitro was not able to protect streptoly sin-sensitive monooxygenases from the inhibition. The addition of stre ptolysin O (0.01 - 0.8 HU/mL) into the cytosol-containing medium did n ot significantly influence the activity of procainamide N-acetyltransf erase. Immunomodulators picibanil (OK 432) and human recombinant inter feron alpha 2A which are known to suppress oxidative metabolism in viv o in humans and animals, were without effect either on the cytochrome P-450-dependent monooxygenases or on the N-acetyltransferase activity when administered in vitro at the doses real in their clinical applica tion (0.001 - 0.1 KE/mL of picibanil and 10 - 500 U/mL of alpha-interf eron).