Dose-related effects of perfluorodecanoic acid on growth, feed intake and hepatic peroxisomal β-oxidation

The effects of the persistent peroxisome proliferator, perfluorodecanoic acid (PFDA), on growth, feed intake and the enzyme activities associated with peroxisomal β-oxidation were studied in female Sprague Dawley rats. Rats received one of six levels of PFDA (0, 0.3, 1.0, 3.0, 10.0 or 30.0 mg/kg/injection) in four IP doses at 2-week intervals. Rats with cumulative doses of ≤ 12.0 mg/kg did not differ from control rats in growth or feed intake, while rats receiving cumulative doses of ≥40 mg/kg lost weight and decreased their feed intake. Rats which received cumulative doses between these levels increased their feed intake but did not significantly alter their body weight. Total peroxisomal β-oxidation was decreased in a dose-related manner, whereas the liver to body weight ratio and the activities of individual enzymes comprising the peroxisomal β-oxidation system, namely fatty acyl-CoA oxidase, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and thiolase, were increased. This study clearly shows that the inhibition of peroxisomal ß-oxidation by PFDA is not reflected in the in vitro measurement of the individual enzyme activities comprising this pathway.