Extrahepatic xenobiotic metabolism in North-European freshwater fish

Lindström-Seppä, Pirjo; Koivusaari, Ulla; Hänninen, Osmo

doi:10.1016/0306-4492(81)90137-4

Cited by 34 publications

(18 citation statements)

References 9 publications

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“…The gill also contains a cytochrome P450 monooxygenase system similar to that in the liver. However, CYP1A activity in the gill usually shows a much lower activity compared to that in the liver [30,31]. Therefore, in the present study, the delayed peak of CYP1A mRNA induction in the gill of βNF‐treated fish relative to the hepatic counterpart may result from its lower catalytic rate.…”

Section: Discussionmentioning

confidence: 69%

Molecular cloning of cytochrome P4501A cDNA of medaka (Oryzias latipes) and messenger ribonucleic acid regulation by environmental pollutants

Ryu

Lee

et al. 2004

Enviro Toxic and Chemistry

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The sequence of cytochrome P4501A (CYP1A) cDNA of medaka (Oryzias latipes) was determined, and its messenger ribonucleic acid (mRNA) regulation by beta-naphthoflavone (betaNF) was evaluated. The determined cDNA sequence contained 2,349 base pairs (bp), and the open reading frame contained a total of 1,563 bp encoding 521 predicted amino acids. The induction of CYP1A mRNA in medaka was evaluated using reverse transcription-polymerase chain reaction. The concentration-dependent induction of CYP1A mRNA in the liver was observed after exposure to betaNF at nominal concentrations of 20, 100, and 500 microg/L for 2 d. Time-dependent changes of CYP1A mRNA levels were also observed in the liver, gill, gut, and caudal fin tissues of medaka exposed to 100 microg/L of betaNF for 7 d. Our results showed that the degree of CYP1A mRNA induction in the gill, gut, and caudal fin after exposure to betaNF was relatively higher than that in the liver, possibly because of low basal levels of CYP1A mRNA in the gill, gut, and caudal fin of nonexposed fish. The induction of medaka CYP1A mRNA was also observed after exposure to an environmental sample, landfill leachate. The CYP1A mRNA inductions in the gill, gut, and caudal fin were also higher than that in the liver as shown in the betaNF-treated groups. These results show that CYP1A mRNA determination in the gill, gut, and caudal fin, which are in direct contact with the polluted water, may become a useful method for monitoring CYP1A-inducible chemicals.

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Section: Discussionmentioning

confidence: 69%

Molecular cloning of cytochrome P4501A cDNA of medaka (Oryzias latipes) and messenger ribonucleic acid regulation by environmental pollutants

Ryu

Lee

et al. 2004

Enviro Toxic and Chemistry

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“…In contrast, intestinal activity in our study was approximately equal to or exceeded that in the liver of mummichog from all sites tested. Similarly, the activity of intestinal UDP-glucuronosyltransferase, another conjugative enzyme, was approximately equal to that of liver in several fish species tested (Lindstr6m-Sepp~i et al 1981).…”

Section: Discussionmentioning

confidence: 96%

Glutathione S-transferase in intestine, liver and hepatic lesions of mummichog (Fundulus heteroclitus) from a creosote-contaminated environment

et al. 1991

Fish Physiol Biochem

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Cytosolic glutathione S-transferase (GSH transferase) activity towards 1-chloro-2,4-dinitrobenzene (CDNB) was elevated approximately three to four-fold in intestine and liver of mummichog (Fundulus heteroclitus) collected from a creosote-contaminated site in the Elizabeth River, Virginia. Intestinal GSH transferase activity at the most heavily contaminated site, at a moderately contaminated site and at a relatively clean site averaged 3.64, 2.83 and 1.11µmoles/min/mg respectively, while values for liver at these sites averaged 2.84, 1.75 and 0.93µmoles/min/mg. In addition, densitometric tracings of sodium dodecylsulfate-polyacrylamide gels of intestine and liver cytosol revealed a similar trend in the staining intensity of a 25.8 kD protein band, which lies within the molecular weight range of GSH transferase subunits. Activity in putative preneoplastic and neoplastic hepatic lesions of fish collected from the creosote-contaminated site was not significantly different from that of adjacent normal tissue. In the laboratory, dietary betanaphthoflavone (ßNF) treatment resulted in a three-fold increase in intestinal GSH transferase. Hepatic GSH transferase activity in the same fish was not affected by dietary ßNF although hepatic monooxygenase activity, measured as ethoxyresorufin O-deethylase (EROD), was. The results of this study indicate a response of the intestinal detoxification system to environmental contaminants and supports previous studies on the importance of intestinal metabolism of foreign compounds. Further, our results indicate the trend towards elevated GSH transferase in liver of feral fish could not be attributed to a cancerous disease state in these fish but indicates chemical induction in this organ as well.

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“…The CaE activity in both gill and liver microsomes was very high relative to many other xenobiotic biotransformation pathways. For example, the activity of several mixed‐function oxygenases (e.g., 7‐ethyoxycoumarin‐ O ‐deethylase; 3,4‐benzpyrene hydroxylase) and UDP‐glucuronyltransferase in rainbow trout hepatic microsomes is typically less than 1 nmol/min/mg protein [21,22]. The CaE activity in rainbow trout hepatic microsomes was similar to the activity of glutathiones‐transferase in rainbow trout [23].…”

Section: Discussionmentioning

confidence: 99%

Tissue carboxylesterase activity of rainbow trout

Barron

Charron

Stott

et al. 1999

Enviro Toxic and Chemistry

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The activity of carboxylesterase (CaE), a class of nonspecific serine hydrolases, was evaluated in vitro in tissues and microsomes of rainbow trout and compared to esterase activity in rats, other fish species, and embryo to adult life stages of trout. Trout gill and liver microsomes exhibited substantial CaE activity and limited variation over the range of 2 to 40°C, with a temperature optimum of approximately 22°C. Trout sera and rat liver microsomes exhibited a temperature optimum of approximately 35 to 40°C. The CaE of trout liver (maximum reaction rate [Vmax] = 672 nmol/min/mg microsomal protein) was four times less than in rats. Apparent Michaelis constant (Km) values ranged from 28 (trout liver) to 214 (trout sera) μM. Values of Vmax/Km suggested that in vivo CaE activity of trout liver would be about three times higher than serum, 135 times higher than gill, and three times lower than rat liver. The CaE activity in whole rainbow trout homogenates significantly increased 300% per gram of tissue to 1,200% per milligram of protein between the yolk‐sac and juvenile stages. The CaE activity of whole fish homogenates was not significantly different in juvenile rainbow trout, channel catfish, fathead minnows, and bluegill. The results demonstrate that rainbow trout had high esterase activity over a broad range of temperatures, that CaE activity significantly increased between the yolk‐sac and juvenile life stages, and that variation between the CaE activity in trout and three other families of freshwater fish was limited. The CaE activity in fish is expected to substantially influence the accumulation and toxicity of pesticides and other esters entering the aquatic environment.

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Extrahepatic xenobiotic metabolism in North-European freshwater fish

Cited by 34 publications

References 9 publications

Molecular cloning of cytochrome P4501A cDNA of medaka (Oryzias latipes) and messenger ribonucleic acid regulation by environmental pollutants

Molecular cloning of cytochrome P4501A cDNA of medaka (Oryzias latipes) and messenger ribonucleic acid regulation by environmental pollutants

Glutathione S-transferase in intestine, liver and hepatic lesions of mummichog (Fundulus heteroclitus) from a creosote-contaminated environment

Tissue carboxylesterase activity of rainbow trout

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