Research in my laboratory is focused on characterizing the regulation and catalytic activity of P450 2E1 (CYP2E1), and examining the effect of antioxidants on stress signaling pathways and P450-dependent metabolism. The level of CYP2E1 is increased by alcohol consumption, and it is hypothesized that many ethanol-associated toxicities are due to the induction of this enzyme in hepatic and extrahepatic tissues. For example, an increased hepatotoxicity of acetaminophen is thought to be due to metabolism of this commonly used over-the-counter pain medication to a reactive metabolite by higher levels of CYP2E1. The induction of CYP2E1 also is associated with an increased generation of active oxygen species that can initiate cellular damage. Since the degree of damage is related to the level of the enzyme, it is important to find those factors that control its intracellular concentration and to identify compounds that can alter its metabolic activity and expression. The research in my laboratory utilizes ce ll lines expressing the normal CYP2E1 and selectively modified forms of the enzyme to identify those regions important in its degradation. In addition, the expression is monitored in genetic models of iron overload where induction of CYP2E1 could exacerbate drug-induced toxicity. The effect of constituents of natural products such as those found in herbal tinctures and alcoholic beverages on P450 dependent expression and metabolism are also being investigated. The metabolic activity of CYP2E1 and other P450s toward endogenous compounds such as lipids, sterols and steroids is being investigated using state-of-the art LC/MS methodologies.