Abstract
The carcinogenic effects of 1, 2-dimethylhydrazine (DMH) were investigated in virgin female Japanese house musk shrews, Suncus murinus (family: Soracidae, order: Insectivora). From 6 weeks of age, 15 shrews were given 14 doses of DMH (40mg per kg, s.c.), administered weekly (group 1) and another 15 animals were given 28 doses of DMH (20mg per kg, s.c.), also administered weekly (group 2); 5 untreated shrews served as controls. A high incidence of musk gland tumors, and some other tumors (carcinomas of the small intestine, pulmonary adenoma, liver adenoma, and leukemia) were induced in DMH-treated shrews, whereas no such tumors were seen in untreated shrews up to 60 weeks of age. Musk gland tumors developed in 82% (9/11) of animals in group I and in 92% (12/13) of animals in group 2 at 36 to 60 weeks of age. DMH, a colonotrophic carcinogen in rodents, did not evoke colon cancers in shrews.
