Biochemical and histological responses in rainbow trout (Oncorhynchus mykiss) exposed to 2,3,4,7,8-pentachlorodibenzofuran

Journal Article · Thu Jan 01 04:00:00 EST 1998 · Environmental Toxicology and Chemistry

DOI:https://doi.org/10.1002/etc.5620170521· OSTI ID:675491

Brown, S B; Evans, R E; Lockhart, W L ^[1]; Delorme, P D; Ward, F J ^[2]; Muir, D C.G. ^[3]

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1. Dept. of Fisheries and Oceans, Winnipeg, Manitoba (Canada). Freshwater Inst.
2. Univ. of Manitoba, Winnipeg, Manitoba (Canada). Dept. of Zoology
3. Environment Canada, Burlington, Ontario (Canada). National Water Research Inst.

Rainbow trout were given an intraperitoneal injection of corn oil containing 0 or 8.8 nmol (3 {micro}g) [{sup 14}C]2,3,4,7,8-pentachlorodibenzofuran (P{sub 5}CDF)/kg and were then held on a light cycle that induced spawning 10 months later. At 5- to 6-week intervals, blood samples were collected to monitor plasma levels of 17{beta}-estradiol (E{sub 2}), testosterone (T), thyroxine (T{sub 4}), 3,5,3{prime}-triiodo-L-thyronine (T{sub 3}), and calcium; packed cell volume (PCV); and differential blood cell counts. Fish were sacrificed after spawning to examine tissue P{sub 5}CDF concentration, liver ethoxyresorufin-O-deethylase (EROD), liver vitamins (retinoids and tocopherol), histology (liver, thyroid), and growth parameters. The P{sub 5}CDF injections produced tissue 2,3.7,8-tetrachlorodibenzo-p-dioxin toxic equivalent concentrations comparable to those reported in salmonids from contaminated areas. Highest P{sub 5}CDF concentrations occurred in gut and liver, but muscle accounted for the greatest proportion of the dose. Plasma hormone and calcium concentrations followed predicted seasonal patterns in both control and exposed fish. PCV was unchanged by repeated blood sampling but differential blood cell counts showed adaptive responses to blood removal. The P{sub 5}CDF exposure caused transient reductions in circulating lymphocytes and elevated EROD. Additionally, P{sub 5}CDF increased liver size and depleted retinoid stores in male fish. Liver histology, somatic growth, and gonadal development were unaltered by P{sub 5}CDF during the first reproductive cycle after exposure.

• Sponsoring Organization: USDOE
• OSTI ID: 675491
• Journal Information: Environmental Toxicology and Chemistry, Journal Name: Environmental Toxicology and Chemistry Journal Issue: 1 Vol. 17; ISSN 0730-7268; ISSN ETOCDK
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BENZOFURANS
BIOLOGICAL INDICATORS
BIOLOGICAL MARKERS
TISSUE DISTRIBUTION
TROUT
WATER POLLUTION