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Pulmonary adenoma and endocrine cell hyperplasia in Syrian golden hamster treated with 4-nitroquinoline 1-oxide
1Department of Pathology, Yokohama City University, School of Medicine, Japan.
Abstract:
Chronic effects of 4-nitroquinoline 1-oxide (4 NQO) on the lungs of Syrian golden hamsters were studied. 4 NQO was subcutaneously injected weekly for 3 weeks at a dose of 20 mg/kg body weight. The animals were sacrificed at the 65th and 80th experimental weeks. Two cases of pulmonary adenomas were demonstrated in the 10 4 NQO-treated animals at the 80th week, and the tumor cells contained cytoplasmic lamellar inclusion bodies. In a previous study, we reported 4 NQO- induced pulmonary endocrine cell hyperplasias in the 4 NQO-treated hamster after the 20th experimental week (Jpn. J. Cancer Res., 77, 1986). In the present study, 12 pulmonary endocrine cell hyperplasias were recognized in serial sections of the 24 treated animals. The hyperplastic lesions showed positive immunoreactivity to calcitonin. The hyperplastic lesion did not develop to pulmonary endocrine cell neoplasm.
Insights
The chemical 4-nitroquinoline 1-oxide (4 NQO) caused lung tumors and endocrine cell hyperplasia in hamsters. These hyperplastic lesions showed calcitonin but did not progress to neoplasm.
Area of Science:
- Oncology
- Toxicology
- Pulmonary Medicine
Background:
- 4-nitroquinoline 1-oxide (4 NQO) is a known carcinogen.
- Previous research indicated 4 NQO induces pulmonary endocrine cell hyperplasias in hamsters.
Purpose of the Study:
- To investigate the chronic effects of 4-nitroquinoline 1-oxide (4 NQO) on Syrian golden hamster lungs.
- To characterize the development and nature of 4 NQO-induced pulmonary lesions.
Main Methods:
- Syrian golden hamsters received weekly subcutaneous injections of 4 NQO (20 mg/kg) for 3 weeks.
- Animals were sacrificed at 65 and 80 weeks post-injection.
- Pulmonary tissues were examined histologically, including serial sectioning and immunoreactivity for calcitonin.
Main Results:
- Two cases of pulmonary adenomas were observed in 4 NQO-treated hamsters at 80 weeks, with tumor cells showing lamellar inclusion bodies.
- Twelve instances of pulmonary endocrine cell hyperplasia were identified in 24 treated animals.
- These hyperplastic lesions were immunoreactive to calcitonin and did not progress to neoplasm.
Conclusions:
- Chronic exposure to 4 NQO can induce pulmonary adenomas in Syrian golden hamsters.
- 4 NQO also causes calcitonin-positive pulmonary endocrine cell hyperplasias, which appear to be a stable, non-neoplastic lesion.