Effects of 28 days silicon dioxide aerosol exposure on respiratory parameters, blood biochemical variables and lung histopathology in rats
Effects of 28 days silicon dioxide aerosol exposure on respiratory parameters, blood biochemical variables and lung histopathology in rats
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DOI：
10.1016/j.etap.2012.07.009
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发表时间：
2012-11-01
影响因子：
4.3
通讯作者：
Vijayaraghavan, R.
中科院分区：
文献类型：
--
作者：
Deb, Utsab;Lomash, Vinay;Vijayaraghavan, R.
对大鼠进行了为期28天的二氧化硅气溶胶（150,300 mg/m(3)）的吸入毒性研究。使用识别呼吸模式变化的计算机程序监测暴露期间呼吸变量的变化。与对照组相比，暴露于气溶胶引起潮汐量随时间的减少，呼吸频率增加。在暴露后第28天记录生化指标和组织病理学观察。血浆碱性磷酸酶、乳酸脱氢酶和血管紧张素转换酶活性与对照组相比呈浓度依赖性增加。血浆酶活性增高提示肺内皮损伤，肺膜通透性增高。肺组织病理学观察证实浓度依赖性肉芽肿性炎症、纤维化和蛋白变性。在300 mg/m(3)二氧化硅气溶胶暴露组，在高倍镜下观察到被成纤维细胞包围的单核细胞聚集物。潮气量的减少和呼吸频率的增加可能是由于肺泡壁增厚导致肺泡容积减少和肺组织弹性降低所致。在本研究中，组织学和生化数据的趋势与呼吸数据一致。本研究首次报道了二氧化硅气溶胶暴露28天期间呼吸变量的变化。(C) 2012 Elsevier B.V.版权所有
Inhalation toxicity of silicon dioxide aerosol (150, 300 mg/m(3)) daily over a period of 28 days was carried out in rats. The changes in respiratory variables during the period of exposure were monitored using a computer programme that recognizes the modifications of the breathing pattern. Exposure to the aerosol caused a time dependent decrease in tidal volume, with an increase in respiratory frequency compared to the control. Biochemical variables and histopathological observation were noted at 28th day following the start of exposure. Biochemical markers of silica induced lung injury like plasma alkaline phosphatase, lactate dehydrogenase and angiotensine converting enzyme activities increased in a concentration dependent manner compared to control. Increase in the plasma enzymatic activities indicates endothelial lung damage, increased lung membrane permeability. Histopathological observation of the lungs confirmed concentration dependent granulomatous inflammation, fibrosis and proteinacious degeneration. Aggregates of mononuclear cells with entrapped silica particles circumscribed by fibroblast were observed in 300 mg/m(3) silica aerosol exposed group at higher magnification. Decrease in tidal volume and increase in respiratory frequency might be due to the thickening of the alveolar wall leading to a decreased alveolar volume and lowered elasticity of the lung tissue. The trends in histological and biochemical data are in conformity with the respiratory data in the present study. This study reports for the first time, the changes in respiratory variables during silica aerosol exposure over a period of 28 days. (C) 2012 Elsevier B.V. All rights reserved.