Non-linear kinetics of microsomal styrene monooxygenase after phenobarbital pre-treatment

Summary Pretreatment of rats with phenobarbital, but not with 3-methylcholanthrene, induces liver microsomal styrene monooxygenase. Under these conditions the kinetic profile is not linear and can be divided into 2 distinct curves. Evidence is presented indicating that the combined treatment with phenobarbital and CoCl₂ destroy the high affinity enzyme, suggesting that the native cytochrome is less sensitive to the action of CoCl₂.This paper was supported by grant No. 181-77-ENVI I awarded by EEC.