肌上皮细胞在大鼠腮腺萎缩过程中的转归

目的 研究大鼠腮腺主导管结扎后萎缩腮腺内肌上皮细胞（MEC）的转归规律。方法 通过结扎大鼠右侧腮腺主导管诱导腺体萎缩，采用苏木精-伊红（HE）染色观察正常腮腺及导管结扎后1、3、5、7、14、21、30、60、 100、150 d萎缩性腮腺的组织学变化，并采用免疫组织化学染色方法定量分析MEC在腮腺萎缩不同时间点的数量及分 布情况。结果 组织学观察发现：腮腺主导管结扎5 d后，大部分腺泡细胞出现凋亡丧失，在腺体萎缩过程中形成 大量导管样结构，间质逐渐纤维化并伴有炎性细胞浸润。免疫组织化学染色定量分析结果显示：导管结扎后5 d 内，MEC数量快速增加，随后其数量增长缓慢，维持在一定的范围内，100 d时MEC数量达到峰值，其后快速减少； 在腮腺萎缩早期，MEC位于腺泡及闰管表面，呈星形或梭形，随着腺体的萎缩，最终呈梭形分布于导管样结构的外层。结论 在导管结扎后5 d内，MEC出现反应性大量增殖，随后数量增长缓慢，维持在一定的范围内；随着腮腺的逐渐萎缩，100 d后MEC数量快速减少。

Changes in the number and distribution of myoepithelial cells during atrophy of rat parotid gland

Objective  To investigate the changes in the number and distribution of myoepithelial cells during atro- phy of the rat parotid gland. Methods  Atrophy of the right parotid was induced by ligating the right stensen duct of rats, histological changes of parotid glands were examined by hematoxylin-eosin（HE） staining during each step of glandular atrophy at the time of 0（control）, 1, 3, 5, 7, 14, 21, 30, 60, 100, and 150 days after ligation. Immunohistochemical labelling was performed to study the changes in number and distribution of myoepithelial cells during atrophy of the rat parotid gland. Results Histological analysis showed disappearance of the acini at 5 d and gradual decrease and fibrosis of the glandular lobules accompanied by the occurrence of duct like structures. Quantitative analysis of myoepithelial cells showed significant increase in number up to day 5 after ligation, then followed by gradual increases at a low level, at last it was followed by a rapid decrease after the total number reached the peak in 100 days. In addition, the acini and intercalated ducts were covered by myoepithelial cells ranged from the shape of spindle to stellate during the early phase of atrophy, while spindle-shaped myoepithelial cells were located at the periphery of duct- like structures in the later phase of atrophy. Conclusion Myoepithelial cells proliferated rapidly up to day 5 after ligation, then followed by gradual increase at a low level, at last it was followed by a rapid decrease after the total number reached the peak in 100 days.