Recovery from Welding-Fume-Exposure-Induced Lung Fibrosis and Pulmonary Function Changes in Sprague Dawley Rats
Autor: | Myung-Haing Cho, Soo-Jin Kim, Young Hyun Chung, Yong Bong Cho, Il Je Yu, Jeong Hee Han, Yong Hwan Lee, Kyung Seuk Song, Jae Hyuck Sung, Kwang Jong Kim, Byung-Gil Choi, Seung-Hee Maeng, Jin Suk Hyun |
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Rok vydání: | 2004 |
Předmět: |
Male
Pathology medicine.medical_specialty Pulmonary Fibrosis Physiology Toxicology Pulmonary function testing Rats Sprague-Dawley Fibrosis Pulmonary fibrosis Tidal Volume medicine Animals Welding Respiratory system Tidal volume Inhalation exposure Inhalation Exposure medicine.diagnostic_test business.industry Pneumoconiosis Body Weight technology industry and agriculture respiratory system medicine.disease Rats Respiratory Function Tests respiratory tract diseases Bronchoalveolar lavage business Bronchoalveolar Lavage Fluid |
Zdroj: | Toxicological Sciences. 82:608-613 |
ISSN: | 1096-0929 |
Popis: | Welder's pneumoconiosis has generally been determined as benign based on the absence of pulmonary function abnormalities in welders with marked radiographic abnormalities. Yet, there have also been several reports on welders with respiratory symptoms, indicating lung function impairment, X-ray abnormalities, and extensive fibrosis. Accordingly, this study attempted to investigate the inflammatory responses and pulmonary function changes in rats during a 60-day welding-fume-inhalation exposure period to elucidate the process of fibrosis. The rats were exposed to manual metal-arc stainless-steel welding fumes (MMA-SS) with total suspended particulate concentrations of 64.8 +/- 0.9 (low dose) and 107.8 +/- 2.6 mg/m3 (high dose) for 2 h per day in an inhalation chamber for 60 days. Animals were sacrificed after the initial 2-h exposure and after 15, 30, and 60 days, and the pulmonary function was also measured every week after the daily exposure. Elevated cellular differential counts were also measured in the acellular bronchoalveolar lavage fluid of the rats exposed to the MMA-SS fumes for 60 days. Among the pulmonary function test parameters, only the tidal volume showed a statistically significant and dose-dependent decrease after 35 to 60 days of MMA-SS welding-fume exposure. When the rats exposed to the welding fumes were left for 60 days to recover their lung function and cellular differentiation, recovery was observed in both the high and low-dose rats exposed up to 30 days, resulting in the disappearance of inflammatory cells and restoration of the tidal volume. The rats exposed for 60 days at the low dose also recovered from the inflammation and tidal volume loss, yet the rats exposed for 60 days at the high dose did not fully recover even after a 60-day recovery period. Therefore, when taken together, the results of the current study suggest that a decrease in the tidal volume could be used as an early indicator of pulmonary fibrosis induced by welding-fume exposure in Sprague Dawley rats, and fibrosis would seem to be preventable if the exposure is short-term and moderate. |
Databáze: | OpenAIRE |
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