Histological alterations in male A/J mice following nose-only exposure to tobacco smoke
| Autor: | Scott J. Richter, R L Morrissey, Narayanan Rajendran, M Misra, S Yee, J T Hamm |
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| Rok vydání: | 2007 |
| Předmět: |
Adenoma
Male Pathology medicine.medical_specialty Lung Neoplasms Health Toxicology and Mutagenesis Respiratory System Nose Toxicology Tobacco smoke Mice Smoke Tobacco medicine Animals Sidestream smoke Lung Inhalation exposure Inhalation Exposure Hyperplasia Inhalation business.industry Body Weight Organ Size medicine.disease medicine.anatomical_structure Particulate Matter business Respiratory tract |
| Zdroj: | Inhalation toxicology. 19(5) |
| ISSN: | 1091-7691 |
| Popis: | The incidence and multiplicity of grossly observed and microscopic lesions of the respiratory tract of A/J mice exposed nose-only to mainstream smoke (50, 200, or 400 mg total particulate matter/m3 from 2R4F cigarettes) was compared to those of filtered air controls. Animals were necropsied at the end of exposure (5 mo) or following 4 or 7 mo of recovery. Lungs were visually inspected for tumors at all necropsies and examined histopathologically at 9 and 12 mo. At 5 mo no tumors were recorded. No significant elevations in tumor incidence or multiplicity were recorded although at 9 mo multiplicity was elevated in the mid-exposure group (0.90 versus 0.55 tumors per animal for controls). At 12 mo, multiplicity was increased over the 9-mo necropsy at all exposures except 200 mg/m3; however, there were no dose-related trends in multiplicity or incidence. Histopathological alterations included hyperplasia, metaplasia, and inflammation of the nose and larynx and proliferative lesions of the lungs. At 9 mo, the multiplicity of focal lung lesions was 1.4 per animal in controls but averaged 1.0 among smoke-exposed groups. There was an inverse relation (p < .059) between smoke concentration and the percentage of hyperplastic lesions at 9 mo. At 12 mo the high-exposure group had slightly increased multiplicity of 2.3 lesions compared with 1.6 among controls, while the percentage of hyperplasic lesions was similar between groups. Nose-only inhalation of mainstream tobacco smoke resulted in chronic inflammatory changes of the respiratory tract yet failed to produce statistically significant changes in tumor incidence or multiplicity. |
| Databáze: | OpenAIRE |
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