Miller B E, Dethloff L A, Hook G E
Lab Invest. 1986 Aug;55(2):153-63.
Several investigators have reported the appearance of hypertrophic type II cells in the lungs of silica-treated rats. The purpose of this study was to isolate and characterize these hypertrophic type II cells. Lungs were digested with trypsin and the released cells were separated by using a flow gradient during centrifugal elutriation. Type II cells from control lungs were distributed in the flow gradient as a single population, whereas type II cells from the lungs of silica-treated rats had a bimodal distribution suggesting the presence of two distinct populations of type II cells; one of these populations appeared hypertrophic (type IIB) and the other appeared normal (type II cells; one of these populations appeared hypertrophic (type IIB) and the other appeared normal (type IIA). These two populations of type II cells from silica-treated rats differed significantly in cell size and their lamellar body content. The mean volume of type IIA and type IIB cells was 350 +/- 38 micron 3 and 523 +/- 29 micron 3, respectively. The mean number of lamellar bodies in type IIA and type IIB cells was 77 +/- 53 and 131 +/- 84 per cell, respectively. The mean volume of lamellar bodies was 0.39 +/- 0.09 micron 3 in type IIA cells and 0.66 +/- 0.10 micron 3 in type IIB cells. Type IIA cells were not significantly different from type II cells from the lungs of untreated rats. The distribution of type II cells from silica-treated lungs was such that 2 weeks after a single intratracheal injection of silica (10 mg/rat) type IIB cells accounted for 39.2 +/- 6.4% of the total type II cells recovered after centrifugal elutriation. The general morphological appearance of the isolated type IIA and type IIB cells was similar to that observed in type II cells isolated from untreated rats. These data indicate that hypertrophic type II cells may be isolated from the lungs of silica-treated rats and separated from normal type II cells thus allowing the role of these unusual type II cells in lung injury and repair to be investigated.
几位研究者报告了在二氧化硅处理过的大鼠肺中出现了肥大的II型细胞。本研究的目的是分离并鉴定这些肥大的II型细胞。用胰蛋白酶消化肺组织，释放出的细胞在离心淘析过程中利用流动梯度进行分离。来自对照肺的II型细胞在流动梯度中呈单一群体分布，而来自二氧化硅处理过的大鼠肺的II型细胞呈双峰分布，提示存在两种不同的II型细胞群体；其中一个群体显得肥大（IIB型），另一个显得正常（IIA型）。来自二氧化硅处理过的大鼠的这两种II型细胞群体在细胞大小和板层小体含量上有显著差异。IIA型和IIB型细胞的平均体积分别为350±38立方微米和523±29立方微米。IIA型和IIB型细胞中板层小体的平均数量分别为每个细胞77±53个和131±84个。IIA型细胞中板层小体的平均体积为0.39±0.09立方微米，IIB型细胞中为0.66±0.10立方微米。IIA型细胞与未处理大鼠肺中的II型细胞无显著差异。来自二氧化硅处理过的肺的II型细胞分布情况是，在单次气管内注射二氧化硅（10毫克/大鼠）后2周，IIB型细胞占离心淘析后回收的总II型细胞的39.2±6.4%。分离出的IIA型和IIB型细胞的一般形态外观与从未处理大鼠分离出的II型细胞中观察到的相似。这些数据表明，肥大的II型细胞可以从二氧化硅处理过的大鼠肺中分离出来，并与正常II型细胞分离，从而能够研究这些异常II型细胞在肺损伤和修复中的作用。
