Effects of perfluorinated compounds on hepatic fatty acid oxidation in avian embryos using a tritium release assay

• Main Author: Westman, Ola
• Format: Bachelor Thesis
• Language: English
• Published: Örebro universitet, Akademin för naturvetenskap och teknik 2009
• Subjects: PFOS; avian toxicology; common guillemot
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-14332

The large use of perfluorinated compounds (PFCs) to produce fluoropolymers in consumer and industrial applications, including insecticides, plastics, non-stick surfaces and fire fighting foams has led to a well known widespread occurrence and high concentrations are found in wild life including avian species. For instance, concentrations of perfluorooctane sulfonate (PFOS) in eggs from the common guillemot in the Baltic Sea are among the highest in the Nordic environment. In our laboratory studies, PFOS has caused early mortality in chicken at doses close to concentrations found in eggs of the Baltic guillemot. The mechanisms behind the avian toxicity are unclear but many studies suggest mechanisms including lipid homeostasis. We have designed a method in which hepatic embryonic tissue from chicken (Gallus domesticus) is used to investigate the effects of PFCs on the β-oxidation of fatty acids. The purpose of this project was to assess the effects of PFOS, perfluorooctanoic acid (PFOA) or perfluorobutane sulfonate (PFBS) on the hepatic fatty acid oxidation using an egg injection technique followed by the use of a tritium release assay with palmitate (16:0) as substrate. The embryos were exposed in ovo and on day 10 of incubation embryo livers are incubated in vitro with tritiated fatty acids. The β-oxidation was significantly induced after exposed to 1 mg/kg PFOS (p = 0.003) and 10 mg/kg PFOS (p = 0.04), and difference in oxidation values was 39% and 34% respectively compared to control. The oxidation effect was not significant (p > 0.05) in samples exposed to PFOA (4 mg/kg) or PFBS (20 mg/kg), however noted, the difference in oxidation values was 18% and 30.5% respectively, compared to control calculated on current average. The results show that in ovo exposure in combination with an in vitro method, using a tritium release assay to detect effects on the β-oxidation of fatty acids in avian embryo hepatic tissue could be a useful method to elucidate possible mechanisms behind avian developmental toxicity.