Abstract
Summary
A newly introduced laboratory species, the rodent Mystromys albicaudatus, or African white-tailed rat, was subjected to oral administration in the drinking water of the carcinogen diethylnitrosamine at 3 dose levels. Male and female animals developed hepatoma, bile duct tumors and some squamous cell carcinomas in the forestomach with a latent period of 22 to 42 weeks. Control animals up to 138 weeks old had no tumors. This species can tolerate higher dose levels of diethylnitrosamine, but tumors developed after a longer latent period than in other laboratory rodent species used for bioassay of chemical carcinogens. This fact, and also the difficulty in reproduction of this species, due to litter size and length of gestation period, suggest that Mystromys albicaudatus is not as suitable for bioassay of carcinogens as currently used rodent species. Additional investigations with other agents are needed to fully support this conclusion.
We thank T. Benjamin, S. Buono and F. Hood for technical assistance, and the staff under J. Zuefle for histologic processing services.
Get full access to this article
View all access options for this article.