Uptake and tissue distribution of waterborne [{sup 3}H]-2,3,7,8-tetrachlorodibenzo-p-dioxin in embryonic fathead minnow (Pimephales promelas)

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:197538

Winden, P J.J. de; Herwig, H J ^[1]

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1. Univ. of Utrecht (Netherlands)

Accumulation of [{sup 3}H]tetrachlorodibenzo-p-dioxin ([{sup 3}H]-TCDD) was studied in embryos of fathead minnow (Pimephales promelas), to evaluate this species` high sensitivity to this compound in relation to internal concentrations. Pathological alterations during fathead minnow early development were described previously at aqueous concentrations ranging from 0.1--50 ng/l. Fertilized eggs and developing embryos were exposed to [{sup 3}H]TCDD (32 mCi/{micro}mol) in 100 ml of water (24 hour static-renewal procedure), until onset of hatch. With 24 hour intervals, radioactivity was measured in exposure water and embryos using liquid scintillation counting. Radioactivity in embryonic tissue was determined in whole body homogenates, obtained by extraction with Lumasolve. Collection of outcoming air from the ventilated exposure medium in aceton revealed no loss of TCDD as a result of evaporation. Binding of TCDD to glass, however, appeared considerable and highly variable (25--50% after 24 hrs). [{sup 3}H]-TCDD levels in exposure water declined from 10 ng/l to < 1 ng/l in 24 hrs (reduction of 85--90%). Fathead minnow eggs or embryos (N = 60), exposed to an initial level of 10 ng [{sup 3}H]TCDD/l, accumulated approximately 3--15% of the applied toxicant in a 24 hr period. During 5 days of exposure (daily medium refreshment), uptake of TCDD increased linearly from 1--2 pg/embryo (day 1) to 9--10 pg/embryo (day 5). Hatching took place in fresh water, resulting in some elimination of TCDD to a level of 6--7 pg/embryo at day 6. The present data demonstrate high toxicity of TCDD in fathead minnow early life stages. At day 3 of embryonic development, accumulation of 5--7 pg [{sup 3}H]-TCDD per embryo causes severe hemodynamic disturbances. Microautoradiography is currently applied to study tissue distribution of [{sup 3}H]-TCDD during embryogenesis.

• OSTI ID: 197538
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AUTORADIOGRAPHY
DIOXIN
EMBRYOS
FATHEAD MINNOW
ONTOGENESIS
PATHOLOGICAL CHANGES
SENSITIVITY
TISSUE DISTRIBUTION
TRACER TECHNIQUES
TRITIUM COMPOUNDS
WATER POLLUTION