Cholestyramine-Enhanced Fecal Elimination of Carbon-14 in Rats after Administration of Ammonium [14C]Perfluorooctanoate or Potassium [14C]Perfluorooctanesulfonate

Abstract

Cholestyramine-Enhanced Fecal Elimination of Carbon-14 in Rats after Administration of Ammonium [14C]Perfluorooctanoate or Potassium [l4C]Perfluorooctanesulfonate. JOHNSON, J. D., GIBSON, S. J., AND OBER, R. E. (1984). Fundam. Appl. Toxicol. 4, 972–976. After a single intravenous dose of ammonium [l4C]perfluorooctanoate ([14C]PFO, 13.3 mg/kg) or of potassium [14C]perfluorocctanesulfonate ([14C]PFOS, 3.4 mg/kg) to rats, cholestyramine fed daily as a 4% mixture in feed was shown to increase the total carbon-14 eliminated via feces and to decrease liver concentration of carbon-14. Rats were fed cholestyramine in feed for 14 days after administration of [14C]PFO and for 21 days after administration of [14C]PFOS. Control rats were administered radiolabeled fluorochemical but were not treated with cholestyramine. Cholestyramine treatment increased mean cumulative carbon-14 elimination in feces by 9.8-fold for rats administered [14C]PFO and by 9.5-fold for rats administered [14C]PFOS. After [14C]PFO, a mean of 4% of the dose of carbon-14 was in liver of cholcstyramine-trcated rats at 14 days versus 7.6% in control rats; after [14C]PFOS, 11.3% of the dose was in liver at 21 days versus 40.3% in control rats. After administration of either radiolabeled compound, plasma and red blood cell carbon-14 concentrations, which were relatively lower than liver concentrations, were also significantly reduced by cholestyramine treatment.