Table 1.
Incidences of preneoplastic lesions with pathological subtypes in the lungs of ferrets with or without NNK exposure for 24 - 32 weeksa).
| Group | NNK (mg/kg BW) |
Time (weeks) |
n | Preneoplastic lesions |
No. of preneoplastic lesion subtypes |
|||
|---|---|---|---|---|---|---|---|---|
| Positive animal | % Incidence | SMb) | SDc) | AAHd) | ||||
| 1 | None | 26 | 8 | 0 | 0 | 0 | 0 | 0 |
|
| ||||||||
| 2 | 200 | 24 | 6 | 6 | 100 | 2 | 3 | 4 |
|
| ||||||||
| 3 | 200 | 26 | 10 | 10 | 100 | 4 | 8 | 6 |
|
| ||||||||
| 4 | 200 | 32 | 6 | 5 | 83.3 | 1 | 1 | 3 |
a)
Including the data of dead animals during the experiment period. Some ferrets developed more than one type of pathologic lesions.
b)
SM: squamous metaplasia.
c)
SD: squamous dysplasia.
d)
AAH: atypical adenomatous hyperplasia.