ToxSci Advance Access originally published online on March 31, 2006
Toxicological Sciences 2006 92(1):143-156; doi:10.1093/toxsci/kfj181
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Published by Oxford University Press 2006.
The Utility of the Guppy (Poecilia reticulata) and Medaka (Oryzias latipes) in Evaluation of Chemicals for Carcinogenicity






* Environmental Medicine and Diseases Program and
Environmental Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709;
Gulf Coast Research Laboratory, University of Southern Mississippi, Ocean Springs, Mississippi 39566;
Experimental Pathology Laboratories, Inc., Herndon, Virginia 20172; and ¶ Pathology Associates, Inc., Cary, North Carolina 27513
Received February 15, 2006; accepted March 29, 2006
There has been considerable interest in the use of small fish models for detecting potential environmental carcinogens. In this study, both guppies (Poecilia reticulata) and medaka (Oryzias latipes) were exposed in the aquaria water to three known rodent carcinogens for up to 16 months. Nitromethane, which caused mammary gland tumors by inhalation exposure in female rats, harderian gland and lung tumors in male and female mice, and liver tumors in female mice by inhalation, failed to increase tumors in either guppies or medaka. Propanediol, which when given in the feed was a multisite carcinogen in both sexes of rats and mice, caused increased liver tumors in male guppies and male medaka. There was reduced survival in female guppies and no increased tumors in female medaka. 1,2,3-Trichloropropane, which when administered by oral gavage was a multisite carcinogen in both sexes of rats and mice, caused an increased incidence of tumors in the liver of both male and female guppies and medaka and in the gallbladder of male and female medaka. The results of this study demonstrate that for these three chemicals, under these specific exposure conditions, the fish appear less sensitive and have a narrower spectrum of tissues affected than rodents. These results suggest that fish models are of limited utility in screening unknown chemicals for potential carcinogenicity.
Key Words: bioassays; small fish models; medaka; guppy; rodent carcinogens; nitromethane; propanediol; trichloropropane.