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Title: Biological (molecular and cellular) markers of toxicity. Final report, September 15, 1988 - September 14, 1991

Several molecular and cellular markers of genotoxicity were adapted for measurement in the Medaka (Oryzias latipes), and were used to describe the effects of treatment of the organism with diethylnitrosamine (DEN). NO{sup 6}-ethyl guanine adducts were detected, and a slight statistically significant, increase in DNA strand breaks was observed. These results are consistent with the hypothesis that prolonged exposure to high levels of DEN induced alkyltransferase activity which enzymatically removes any O{sup 6}-ethyl guanine adducts but does not result in strand breaks or hypomethylation of the DNA such as might be expected from excision repair of chemically modified DNA. Following a five week continuous DEN exposure with 100 percent renewal of DEN-water every third day, the F values (DNA double strandedness) increased considerably and to similar extent in fish exposed to 25, 50, and 100 ppM DEN. This has been observed also in medaka exposed to BaP.
Authors:
; ; ;
Publication Date:
OSTI Identifier:
7044713
Report Number(s):
ORNL/M--1845
ON: DE92019190
DOE Contract Number:
AC05-84OR21400
Resource Type:
Technical Report
Research Org:
Oak Ridge National Lab., TN (United States)
Sponsoring Org:
Department of Defense (DOD), Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; CARCINOGEN SCREENING; CARCINOGENS; BIOASSAY; MUTAGEN SCREENING; MUTAGENS; TERATOGEN SCREENING; TERATOGENS; BENZOPYRENE; BIOLOGICAL INDICATORS; DNA ADDUCTS; FISHES; NITROSAMINES; PROGRESS REPORT; ADDUCTS; AMINES; ANIMALS; AQUATIC ORGANISMS; AROMATICS; CONDENSED AROMATICS; DOCUMENT TYPES; HYDROCARBONS; NITROSO COMPOUNDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; SCREENING; VERTEBRATES 560300* -- Chemicals Metabolism & Toxicology