EXPRESSION OF MULTIPLE FORMS OF BRAIN CYTOCHROME-P450

Multiple forms of cytochrome P450 (P450) in brain tissue have been dem onstrated to be expressible in brain tissue using polymerase chain rea ction (PCR) techniques, Northern blotting, hydroxylation activity asse ssment and cloning approaches. The antidepressant drug imipramine is m etabolized by brain microsomes to multiple products by pathways inhibi table by quinidine, 7,8-benzoflavone, and ketoconazole, well-known inh ibitors of P450-catalyzed reactions. Moreover, PCR studies revealed th at a number of P450s are expressible in brain tissue and in glioma C6 cells. Quantitative PCR studies further demonstrated the response of m any of these forms to induction in agreement with hydroxylation activi ty results.