正己烷染毒大鼠结膜及泪腺损伤的组织病理学和超微结构观察

Histopathological and ultrastructure observation of conjunctiva and lacrimal gland in rats exposed to n-hexane

目的研究正己烷染毒大鼠结膜和泪腺组织的损伤。方法32只雄性SD大鼠随机分成对照组和染毒组。采取静式吸入染毒方式,正己烷浓度为35.2g/m3,染毒1、3、7、14d后处死大鼠,对照组为吸入空气的空白对照。观察结膜和泪腺组织的组织病理学和超微结构的改变。结果染毒7d和14d大鼠结膜上皮细胞微绒毛减少。部分基底细胞出现核固缩和核内空泡,线粒体水肿、缩小或消失。染毒14d大鼠结膜杯状细胞明显减少。正己烷染毒大鼠的泪腺细胞出现水肿和淋巴细胞浸润。结论正己烷染毒大鼠的结膜和泪腺组织出现明显的损害,将会影响正常泪膜稳定性的维持,导致眼表疾病的发生。

Objective As an organic solvent, n-hexane has been used widely. Its low-toxicity to human tissue has been determined. However, its accumulation and toxicity to nerve system is being emphasized. This study was to investigate the injury in the conjunctiva and lacrimal gland of rats exposed to n-hexane. Methods Thirty-two SD male rats were randomly divided into control group and four experimental groups. The rats of experimental groups inhaled 35.2 g/m^3 n-hexane statically for 1,3,7 and 14 days respectively,and rats in the control group inhaled air. Histopathological and uhrastructure changes of the conjunctiva and the lacrimal gland of rats were analyzed under the optical and electron microscope. Results The concentration of n-hexane in blood of ratsin different experimental groups was （242.91 ± 59.68 ） , （668.77 ± 221.74 ） , （ 1 021.21 ± 545.71 ） and （ 1 140. 42 ± 468.44）μg/L, showing a significant decrease in comparison with control group（ 〈 0. 1 μg/L）. In the rats exposed to n-hexane for 7 days and 14 days, microvillus of conjunctiva epithelium were decreased. In some basal cells, some pyknotic nucleus and vacuole, swelling,dwindle or absence of mitochondria were seen. The number of conjunctiva goblet cells compared with the control group descended in n-hexane group of 14 days （ P 〈 0. 05 ）. In the rats exposed to n-hexane, edema of lacrimal grand cells and lymphocytic infiltration were showed. Conclusion Conjunctiva and lacrimal gland tissue are damaged in the rats exposed to n- hexane,thus affecting tear film stability and leading to ocular surface disease.