INDUCED CYTOCHROME-P-450 IN INTESTINE AND LIVER OF SPOT (LEIOSTOMUS-XANTHURUS) FROM A POLYCYCLIC AROMATIC HYDROCARBON CONTAMINATED ENVIRONMENT

Levels of total cytochrome P-450, of specific P-450 (determined immunologically with MAb 1-12-3 and referred to as P-450E) and ethoxyresorufin O-deethylase (EROD) were elevated in intestine and liver microsomes of spot (Leiostomus xanthurus) collected from the Elizabeth River, a polycyclic aromatic hydrocarbon (PAH) contaminated tributary of Chesapeake Bay. Fish were collected over a sediment PAH concentration gradient that ranged from 9 to 96 000 μg PAH/kg dry sediment. Intestinal P-450E was near the lower limits of detection in fish collected at the relatively clean sites but was elevated 80- to 100-fold in fish collected from contaminated sites. Intestinal EROD activity exhibited a similar trend. Liver P-450E and associated EROD activity was detectable in all samples and was induced approximately eight-fold at the most heavily contaminated site. Despite the sensitivity of the intestine to PAH inducing agents, intestinal P-450E levels did not correlate well with sediment PAH, whereas liver P-450E did. Instead, the intestinal enzyme was induced to similar and high levels at all contaminated sites. The results suggest that the intestine plays an important role in the absorption and metabolism of dietary PAH and/or other PAH-type inducing agents and that intestinal P-450E may be a useful indicator of exposure to these compounds via the diet. © 1990.