Brightwell J, Heppleston A G
Inhaled Part. 1975 Sep;4 Pt 2:509-18.
The stathmokinetic technique was used to study quantitatively the proliferative response of cells comprising the alveolar wall of inbred mice which had inhaled coal or quartz. The exposures occupied 4 weeks and the observations continued over an extended period thereafter. Control observations suggested that mitotic inhibition was induced solely by residence in the exposure chamber, since cessation of exposure was quickly followed by a temporary rise of proliferative activity. This feature was not apparent when dust was inhaled, though with comparable exposure to both coal and quartz there was an elevation in mitotoic incidence of alveolar wall cells in dust-free areas of lung at a later interval. In dust-laden areas the rise was less in evidence, a situation that persisted throughout the post-exposure survival. The difference in mitotic incidence between dust-free and dust-containing areas was more evident after coal than after quartz inhalation, whilst in higher concentration a quartz aerosol induced a continued depression of mitotic activity. The proliferative response seen in the alveolar walls of control and dusted mice is most likely to be contributed by the interstitial precursors of alveolar macrophages, cells which are recognized to be marrow derived. The changes observed in mitotic incidence are interpreted in terms of demand for alveolar macrophages according to the nature of the dust and the inintensity of the exposure.
采用静止动力学技术对吸入煤尘或石英的近交系小鼠肺泡壁细胞的增殖反应进行了定量研究。暴露持续4周，此后观察持续了较长一段时间。对照观察表明，有丝分裂抑制仅由暴露于暴露室引起，因为暴露停止后，增殖活性会暂时升高。吸入粉尘时，这一特征并不明显，尽管在相同的煤尘和石英暴露条件下，肺无粉尘区域的肺泡壁细胞有丝分裂发生率在稍后的时间段会升高。在有粉尘的区域，这种升高不太明显，这种情况在暴露后的存活期一直持续。吸入煤尘后，无粉尘区域和含粉尘区域之间的有丝分裂发生率差异比吸入石英后更明显，而在较高浓度下，石英气溶胶会导致有丝分裂活性持续降低。对照小鼠和接触粉尘小鼠肺泡壁中观察到的增殖反应很可能是由肺泡巨噬细胞的间质前体细胞引起的，这些细胞被认为源自骨髓。根据粉尘的性质和暴露强度，观察到的有丝分裂发生率的变化是根据对肺泡巨噬细胞的需求来解释的。
