Immediate and delayed organ-specific effects of perfluorooctane sulfonate (PFOS) and perfluoroactanate (PFOA) on the endocrine system of juvenile salmon exposed through diet

Perfluoric compounds like perfluorooctane sulfonate (PFOS) and perfluorooctane carboxylate (PFOA) are persistent in the environment and their biological effects are still under investigation. The present study was conducted to study the mechanistic effects of these compounds on steroidogenesis in Atlantic salmon (Salmo salar) parr. Salmon parr were exposed to 0.2 mg/kg of PFOS or PFOA. The fish were fed 3 times during a 7 days period followed by one week of depuration. Exposure to PFOA and PFOS did not produce alterations in plasma estradiol (E2) or testosterone (T) levels. Expression profiles of mRNA species involved in steroidogenesis (StAR, P450scc, CYP11β, 20β-HSD and CYP19β) in the brain and kidney indicated both immediate and delayed effects of these perfourinated compounds. Interestingly, while both compounds mediated similar changes in the mRNA expression profiles of steroidogenic genes in the brain, compound specific expression patterns were observed in the kidney. Immunochemical analysis of StAR and P450scc confirmed gene expression analysis. These results provide novel insight into the mechanistic effects and organ differences of perfluorinated compounds on fish steroidogenic pathways.