Abstract

Trichloroethylene (TRI) is one of the most widely used organic solvent in many industries. It is used a degreasing agent, extract and dillution solvents. TRI is metabolized by liver microsomal cytochrome P4SO to reactive intermediates, which are considered responsible for its hepatotoxicity. Cytochrome P450 is a key enzyme in the first step of TRI metabolism resulting in chloral hydrate (CH) formation, which is a rate-limiting step in TRI metabolism. This study was perfomed to find out the change of hepatic cytochrome P450 levels and of electron transport system for P-450 dependent reaction. Intraperitoneal injections of TRI were done to the male Sprague Dawley rats(mean body wights,170+/-10g) in corn oil at the dosage of 150,300,600 mg/kg for 2 days. The results of experiments are following : 1. The contents of microsomal protein, cytochrome P450 and b(5) are tended to be decreased with increasing amount of TRI, but not significantly (p>0.05) . 2. The activity of NADPH-cytochrome P450 reductase is slowly decreased by increasing amount of TRI, but not slgnificantly (p>0.05) . On the other hand, the activity of NADH-b(5) reductase is increased with increasing amount of TRI (p<0.05) 3. The activity of 7-ethoxyresolufin 0-deethylase did not show any critical changes (P>0.05) . This result suggests that the inductive pattern of TRI may not be related to P 450IAl and P450IIB.

• Keywords: Trichloroethylene;Liver microsomal cytochrome P450;7-ethoxyresolufin Odeethylase