Nikula K J, Wilson D W, Dungworth D L, Plopper C G
Department of Pathology, School of Veterinary Medicine, University of California, Davis 95616.
Toxicol Appl Pharmacol. 1988 May;93(3):394-402. doi: 10.1016/0041-008x(88)90042-7.
Adaptation to prolonged ozone (O3) exposure occurs in the tracheal epithelium of rats and is marked by the presence of ciliated cells with uniform short cilia but is not accompanied by shifts in cell populations, altered characteristics of epithelial secretory cell products, increased cell turnover, or elevated tracheal superoxide dismutase activity. The purpose of this study was to test the hypothesis that adaptation is a result of alterations intrinsic to epithelial cells or to the cells and their matrix, and not due to systemic or neural influences. Rats were preexposed to either filtered air (FA) or 0.96 ppm O3 for 8 hr/night for 60 days, and then their tracheae were removed and exposed to 3 ppm O3 in an explant culture system where behavioral, nasal, exudative, and secretory product influences can be eliminated. After exposure to 3 ppm O3 in vitro, quantitative electron microscopic evaluation demonstrated that the epithelia from the FA preexposure group had significantly more necrotic cells and sloughed cells and fewer ciliated cells than the epithelia from the O3 preexposure group. Thus previous exposure to ozone in vivo induces a change in tracheal epithelium which confers resistance to ozone-induced injury in the explant exposure system.
大鼠气管上皮会对长期臭氧（O₃）暴露产生适应性变化，其特征为出现具有均匀短纤毛的纤毛细胞，但细胞群体无变化，上皮分泌细胞产物的特性未改变，细胞更新未增加，气管超氧化物歧化酶活性也未升高。本研究的目的是检验以下假设：适应性变化是上皮细胞本身或细胞及其基质发生改变的结果，而非全身或神经影响所致。将大鼠每晚暴露于过滤空气（FA）或0.96 ppm O₃中8小时，持续60天，然后取出它们的气管，在一个可消除行为、鼻腔、渗出和分泌产物影响的外植体培养系统中，将其暴露于3 ppm O₃。在体外暴露于3 ppm O₃后，定量电子显微镜评估显示，与O₃预暴露组的上皮相比，FA预暴露组的上皮有更多的坏死细胞和脱落细胞，纤毛细胞更少。因此，先前在体内暴露于臭氧会导致气管上皮发生变化，使其在外植体暴露系统中对臭氧诱导的损伤具有抗性。
