COMPARISON OF MOUSE STRAINS FOR SUSCEPTIBILITY TO STYRENE-INDUCED HEPATOTOXICITY AND PNEUMOTOXICITY

Styrene is known to cause both hepatotoxicity and pneumotoxicity in mi ce. Strain differences have been reported by other investigators sugge sting that Swiss mice are less susceptible than non-Swiss mice to styr ene-induced liver damage. in this study, A/J and C57BL/6 mice were fou nd to be similar to non-Swiss albino (NSA) mice in susceptibility wher eas CD-1 (Swiss) mice were more resistant to hepatotoxicity as assesse d by serum sorbitol dehydrogenase levels and pneumotoxicity as determi ned by gamma-glutamyltranspeptidase and lactate dehydrogenase measurem ents in bronchoalveolar lavage fluid. Styrene was hepatotoxic in CD-1 mice treated with pyridine to induce CYP2E1. CYP2E1 apoprotein levels and p-nitrophenol hydroxylase activities in control and pyridine-induc ed mice were similar in the two strains. Hepatic and pulmonary microso mal preparations from both strains metabolized styrene to styrene oxid e at similar rates. CD-1 mice were as susceptible as the NSA mice to t he effects of styrene oxide. The data suggest that there are no differ ences in the bioactivation of styrene to styrene oxide or innate susce ptibility to the active metabolite that would account for the differen ces between the CD-1 and NSA mice.