Influence of Environmental Contamination on Cytochrome P-450 Mixed-Function Oxygenases in Fish: Implications for Recovery in the Wild Harbor Marsh

Levels of hepatic cytochrome P-450 and the catalytic functions benzo[a]pyrene hydroxylase and aminopyrine demethylase were significantly greater in populations of mummichog, Fundulus heteroclitus, sampled from contaminated marshes than in those fish from nearby reference marshes. Aminopyrene demethylase, but not benzo[a]pyrene hydroxylase, was also elevated in fish from one of the reference marshes. The levels of cytochrome P-450 and benzo[a]pyrene hydroxylase were highest in fish from the Wild Harbor Marsh, site of the 1969 Florida spill. A correlation between size and benzo[a]pyrene hydroxylase activity was identified in some of the populations studied, although influence by this factor did not mask the population differences. The results are consistent with the hypothesis that elevated levels of mixed-function oxygenase activity in fish from Wild Harbor are the result of oil spilled 8 yr ago, and that recovery of this marsh is not yet complete. Key words: mixed-function oxygenases, benzo[a]pyrene hydro...