Gavage of fathead minnows (Pimephales promelas) with nanoparticle-based dispersants and water accommodated fraction (WAF) of crude oil

Adult female fathead minnow (Pimephales promelas) were treated by gavage with water, or WAF (water accommodated fraction of oil) alone or in the presence of 50 mg/L hyperbranched polyglycidol (HPG)-nanoparticle dispersant. The treatment occurred four times over two weeks and consisted of 15 ul gavage of each of the treatments described above. There were 8 fish per treatment group. After the treatment, the fish were euthanized with MS222 and severance of the spinal cord and livers were removed and placed into RNAlater. RNA was extracted and analyzed for expression of Cyp1a (Cytochrome P450 1A). The results indicated that the WAF alone induced Cyp1A expression but that the treatment of WAF plus HPG-NP decreased Cyp1A below that shown for WAF alone.