Perfluorodecanoic acid and lipid metabolism in the rat

Alterations in lipid metabolism were axamined in adult male Sprague-Dawley rats seven days after a single intraperitoneal injection of perfluorodecanoic acid (PFDA; 20, 40 or 80 mg/kg). Because PFDA treatment caused a dose-related reduction in feed intake, the response of vehicle-treated rats pair-fed to those receiving PFDA was monitored to distinguish direct effects of the perfluorinated fatty acid from those secondary to hypophagia. Carcass content of lipid phosphorus and free cholesterol decreased in dose-dependent fashion in both PFDA-treated and pair-fed rats. Carcass triacylglycerols diminished in a similar manner, yet PFDA-treated rats at each dose had a higher concentration of neutral acylglycerols than their vehicle-treated, pair-fed counterparts. In vehicle-treated, pair-fed rats at the 80 mg/kg dose level, lipid phosphorus and free cholesterol as a proportion of carcass fat increased, whereas the share of the triacyl-glycerols declined. Because of the higher concentration of triacylglycerols in the carcass of rats treated with 80 mg/kg PFDA, enrichment of lipid phosphorus and free cholesterol in carcass fat was less than in their pair-fed partners. The amount of lipid phosphorus and free cholesterol per hepatocyte was similar in both PFDA-treated rats and their pair-fed partners. Liver triacyl-glycerols were markedly increased in PFDA-treated rats. A similar but less extensive augmentary effect of PFDA on hepatic esterified cholesterol was found. Concentration of triacylglycerols in plasma was not elevated in PFDA-treated rats, in spite of hepatic accumulation of esterified compounds. Also, the plasma level of free fatty acids and 3-hydroxybutyrate was similar in all treatment groups, including those receiving PFDA. Thus, the administration of PFDA appears to divert fatty acids from oxidation toward esterification in the liver.