INDUCTION OF CYTOCHROME-P-450 ENZYMES VIA TOBACCO-SMOKE - A POTENTIALMECHANISM FOR DEVELOPING RESISTANCE TO ENVIRONMENTAL TOXINS AS RELATED TO PARKINSONISM AND OTHER NEUROLOGIC DISEASES

Case-control studies have consistently demonstrated a reduced risk of Parkinsonism in smokers. A potential mechanism of protection is based on the 'induction' of cytochrome P-450 enzymes by polyaromatic hydroca rbons in tobacco smoke. Cytochrome P-450 enzymes are responsible for b iomodification and detoxification of foreign substances. Stimulation o f these enzymes in the olfactory epithelium and in the liver may lead to increased metabolism of xenobiotics, thereby preventing environment al neurotoxins from reaching target organs. Polymorphic expression of this family of isozymes may confer a unique susceptibility to some neu rologic diseases.