Effect of a Prudhoe Bay crude oil on hepatic and renal peroxisomal {beta}-oxidation and mixed-function oxidase activities in rats

The effect of oral administration of a Prudhoe Bay crude oil(PBCO) to male rats (PBCO, 2.6 g/kg body weight, daily) for5–12 days on hepatic and renal microsomal mono-oxygenaseactivities and peroxisomal ß-oxidation has been investigated.PBCO administration leads to liver enlargement. This is associatedwith induction of microsomal cytochrome P-450 levels (1.6- to2.0-fold) and dependent mixed-function oxidase activities (7-ethoxyresorufin-O-deethylaseand 7-pentoxyresorufin-O-depentylase, representing cytochromeP-450I and cytochrome P-450IIB isoenzymes respectively, 9-to15-fold; -oxidation of lauric acid representing the cytochromeP-450IVA1 isoenzyme, 1.4- to 1.5-fold) along with peroxisomalß-oxidation (palmitoyl CoA oxidation, 2- to 5-fold).It was observed that rats exposed to PBCO showed an increasein renal microsomal cytochrome P-450 content (1.6- to 2.3-fold),cytochrome P-450I activity (5- to 8-fold) and -oxidation activity(1.3- to 1.4-fold). However, renal peroxisomal ß-oxidationwas unaltered. Serum total triglycerides were lowered by 41–46%after PBCO exposure. These results suggest that induction ofperoxisomal ß-oxidation and possibly mono-oxygenasesmay be related to the carcinogenic/tumorigenic potential ofcrude oil.