Schiff L J, Byrne M M, Elliott S F, Moore S J, Ketels K V, Graham J A
Scan Electron Microsc. 1981(Pt 2):169-78.
The effects of Mount St. Helens volcanic ash on rings of hamster tracheal epithelium in organ culture were studied. Volcanic ash samples with mass median aerodynamic diameters (MMAD) of 7.7 micrometers and 1.6 micrometers caused markedly different alterations in the tracheal mucosa. Examination by SEM of the ventral epithelial surface of tissue from untreated control explants after 2 weeks in culture showed equal numbers of ciliated and microvillous cells. Examination by SEM of tracheas exposed to the smaller size particles revealed that ash concentrations as low as 1 microgram/ml increased mucous secretion after one 2-hr exposure. After four or nine 2-hr exposures, cells contained cilia that were short and blunt. Ciliary activity after these exposures showed a significant depression in beating frequency. Tracheal ring cultures exposed to the larger volcanic ash particles exhibited moderate cytomorphological changes after one 2-hr exposure at concentrations of 1, 10 and 100 micrograms/ml. As the number of exposures increased, most of the columnar cell layer was lost, resulting in exposure of the basal cells. After nine exposures at the two highest concentrations of ash (10 and 100 micrograms/ml), only a few ciliated cells were remaining. Statistically significant reductions in ciliary activity paralleled the epithelial damage. The degree of epithelial damage and changes in the cilia beating frequency were related to the dose and the number of exposures to the volcanic ash.
研究了圣海伦斯火山灰对器官培养中仓鼠气管上皮环的影响。质量中位空气动力学直径（MMAD）为7.7微米和1.6微米的火山灰样本在气管黏膜中引起了明显不同的改变。培养2周后，对未处理对照外植体组织腹侧上皮表面进行扫描电子显微镜（SEM）检查，发现纤毛细胞和微绒毛细胞数量相等。对暴露于较小尺寸颗粒的气管进行SEM检查发现，在一次2小时暴露后，低至1微克/毫升的火山灰浓度就会增加黏液分泌。在进行四次或九次2小时暴露后，细胞中的纤毛变得短而钝。这些暴露后的纤毛活动显示出跳动频率显著降低。暴露于较大火山灰颗粒的气管环培养物在浓度为1、10和100微克/毫升的情况下进行一次2小时暴露后，出现了中度细胞形态学变化。随着暴露次数的增加，大部分柱状细胞层消失，导致基底细胞暴露。在以两种最高火山灰浓度（10和100微克/毫升）进行九次暴露后，仅剩下少数纤毛细胞。纤毛活动的统计学显著降低与上皮损伤平行。上皮损伤程度和纤毛跳动频率的变化与火山灰的剂量和暴露次数有关。
