Bioavailability to Juvenile Rainbow Trout (Oncorynchus Mykiss) of Retene and Other Mixed-Function Oxygenase-Active Compounds From Sediments

Abstract

Retene (7-isopropyl-1-methylphenanthrene) is a naturally formed polycyclic aromatic hydrocarbon (PAH) that causes teratogenicity in fish larvae and induction of cytochrome P450 (CYP1A) enzymes. Retene occurs at high concentrations (< or =3,300 microg/g dry wt) in surface sediments contaminated by resin acids from pulp mill effluents. To assess the environmental risks of retene, it is important to evaluate conditions affecting its bioavailability and accumulation by fish. Fingerling rainbow trout were exposed to retene-spiked or naturally contaminated sediments and sampled after 4 d to determine liver CYP1A activity and concentrations of retene metabolites in bile as indicators of retene accumulation. Industrially contaminated sediments collected near a bleached kraft pulp and paper mill discharging to Lake Saimaa, Finland, significantly induced trout liver CYP1A activity, indicating accumulation of arylhydrocarbon receptor (AhR)-active ligands. Bile of these fish contained retene metabolites, providing direct evidence that retene is bioavailable, presumably via desorption from sediments. Induction of CYP1A in fish exposed to sediments spiked with retene or benzo[k]fluoranthene supported this conclusion. While the extent of CYP1A induction by spiked sediments declined after storage (i.e., aging), a portion of the spiked PAHs remained bioavailable. However, retene was not the sole CYP1A inducer in industrially contaminated sediments, as shown by induction in fish injected with sediment extracts oxidized to remove labile PAHs but not persistent organochlorine compounds such as chlorinated dioxins and furans.

Caddis larvae (Trichoptera, Hydropsychidae) indicate delaying recovery of a watercourse polluted by pulp and paper industry

“…Similar results were also obtained from the laboratory bioassays, where juvenile rainbow trout were exposed to the sediment in water system (IV). In sediment with water bioassays, Southern Lake Saimaa sediment was used as a positive control (III, IV), and the results indicated EROD-potential as in a similar experimental setup (Oikari et al 2002). The sediment of Southern Lake Saimaa is known to be highly contaminated by retene , Oikari et al 2002) and retene may induce EROD activity already at a nominal concentration of 10 μg l -1 in water .…”

“…In sediment with water bioassays, Southern Lake Saimaa sediment was used as a positive control (III, IV), and the results indicated EROD-potential as in a similar experimental setup (Oikari et al 2002). The sediment of Southern Lake Saimaa is known to be highly contaminated by retene , Oikari et al 2002) and retene may induce EROD activity already at a nominal concentration of 10 μg l -1 in water . The amounts of retene in the Southern Lake Saimaa sediment extract dosed in our study were 7, 14 and 28 μg g -1 fish (III), i.e.…”

“…into the juvenile rainbow trout (III). Sediment extracts were prepared according to Oikari et al (2002), except retene and other labile organic compounds were not removed. Thus the whole range of AhRactivating compounds was included in the exposure.…”

The H4IIE Cell Bioassay as an Indicator of Dioxin-like Chemicals in Wildlife and the Environment

“…Fractionation techniques allow the isolation or removal of specific chemicals in extracts, enabling determination of the contribution of different classes of chemicals to CYP1A induction (Gale et al, 2000). Isolation of PHHs in biological samples can be accomplished using sulfuric acid silica gel during extract preparation to destroy (oxidize) nonchlorinated PAHs (Tillitt et al, 1991;Oikari et al, 2002). Using fractionation methods, the identities of the most active CYP1A-inducing classes of compounds in an extract can be determined.…”

Biomarker induction in tropical fish species on the Northwest Shelf of Australia by produced formation water

“…Similar to the previous study (Codi King et al, 2005a), undertaking the subsequent controlled field study using caged fish. (Flammarion et al, 2002), particularly for 273 persistent pesticides (Levine et al, 1999), polychlorinated biphenyls (Burton et al,274 2002; Haasch et al, 1993), dioxins (Zodrow et al, 2004;Smith, 2003), pulp mill 275 effluents (Oikari et al, 2002), xenoestrogens (Katchamart et al, 2002), spilled crude 276 oil (Jewett et al, 2002), and polycyclic aromatic hydrocarbons (PAHs) (Stagg et al,277 2000). The induction of CYP1A has implications for human fish consumption, as well 278 as for the health status of aquatic organisms (Arinc et al, 2000).…”