Multiplicity of spontaneous lung tumors in CD-1 mice.
The multiplicity of the spontaneous lung tumor in CD-1 mice was investigated in 413 males from 6 different control groups of 2-year carcinogenicity studies with agrochemicals. Among a total of 152 lung tumor bearers, 95 (62.5%) were seen with 1 nodule, 36 (23.7%) with 2 nodules, and 14 (9.2%) with 3 nodules. Three males bore 4 nodules and each of 5, 7, 9 and 10 nodules was seen in one male, respectively. In one control group 20 out of 30 lung tumor bearers had 2 or more nodules presenting a significant heterogeneity among the control groups in terms of the multiplicity of lung tumor nodule.
Toxicology Division, Institute of Environmental Toxicology, Tokyo, Japan.
K
K
Maita
M
M
Hirano
T
T
Harada
K
K
Mitsumori
A
A
Yoshida
K
K
Takahashi
N
N
Nakashima
T
T
Kitazawa
A
A
Enomoto
K
K
Inui
D000818:Animals; D008175:Lung Neoplasms / Q000453:epidemiology / Q000662:veterinary*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012376:Rodent Diseases / Q000453:epidemiology*