Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Comparison of DENA carcinogenesis in two fish species

Thesis/Dissertation ·
OSTI ID:6064812
The present study compared the morphological and biochemical responses of two teleost species to a carcinogenic environmental contaminant. Medaka, Oryzias latipes, are commonly used laboratory fish that are exquisitely sensitive to the tumorigenic effects of mammalian carcinogens. Fathead, Pimephales promelas, are used extensively in aquatic toxicity testing but have proven resistant to many mammalian carcinogens. To determine if morphologic changes leading to tumor formation occurred more slowly in the resistant species or if they progressed to a certain point and then stopped, fish were sacrificed at weekly intervals for up to 41 weeks following exposure to DENA. Livers were serially analyzed by light microscopy and compared across species and to controls. Lower incidence of normal morphology was seen in DENA-exposed fish of both species. Incidence of morphologic lesions were significantly different in the two species. Basophilic foci and spongiosis hepatis were observed only in DENA-exposed medaka. Tumors were observed earlier in the medaka and at a higher frequency. Accumulation and distribution of {sup 14}C-DENA were measured to determine if tumor incidence was proportional to the concentration of DENA and radiolabelled by-products at the target site.
Research Organization:
West Virginia Univ., Morgantown, WV (USA)
OSTI ID:
6064812
Country of Publication:
United States
Language:
English