大鼠萎缩腮腺中肌上皮细胞增殖状态的观察

Observation on myoepithelial cells in atrophic parotid gland of rats by immunohistochemical staining

目的 采用免疫组化双染技术观察大鼠腮腺主导管结扎后萎缩腺体内肌上皮细胞（myoepithelial cell, MEC）的增殖变化规律。方法 采用Wistar大鼠建立腮腺主导管结扎动物模型,结扎大鼠右侧腮腺主导管诱导腺体萎缩,HE染色观察正常腮腺及主导管结扎后1、3、5、7、14、21、30、60、90、120、150、180天萎缩性腮腺的组织学变化,采用免疫组化双重染色法定量分析MEC在腮腺萎缩不同时间点的数量、增殖率及分布情况。结果 HE染色示：主导管结扎后,腮腺腺泡细胞出现凋亡消失,大量导管样结构形成,纤维组织增生并伴有炎性细胞浸润。免疫组化染色示：导管结扎后第3天,MEC发生快速增殖,5天时增殖率达到顶峰,随后MEC增殖率降低,30～150天时MEC增殖率均维持较低水平,180天时难以观察到增殖的MEC且MEC细胞总数显著减少。结论 结扎腮腺导管诱导腺体萎缩的过程中,MEC在萎缩早期表现出较强的增殖能力,5天时达到顶峰,随后增殖活力下降,30～150天MEC增殖活性均处较低水平,180天时已观察不到增殖的MEC。

Purpose To observe the proliferative changes of myoepithelial cells within atrophic gland after the ligation of rat parotid duct with double immunhischemical staining. Methods The parotid duct of Wistar rat was ligated to establish an animal model, and then atrophy of the fight parotid developed. The 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, 90, 120, 150, and 180 days after ligation. Immunohistochemical double staining was performed to quantitatively analyse the changes in number, proliferation rate and distribution of myoepithelial ceils during atrophy of the rat parotid gland. Results Histological observation showed apoptosis of acinar cells and formation of a large number of duct-like structures, fibrous tissue hyperplasia and inflammatory cells infiltration after ligation. Quantitative analysis of immunohistochemical staining results showed that： on the third day after duct ligation, the myoepithelial ceils proliferated rapidly, the proliferation rate reached a peak value on the fifth day and then decreased, on the 30 - 150 days, the proliferation rate was maintained at a low level. It was then difficult to observe the proliferation of myoepithelial cell and the myoepithelial cell number was significantly decreased. Conclusions Myoepithelial cells proliferate rapidly up to day 5 after ligation, then followed by gradual increase at a low level in 30 -50 days, and at last there is a rapid decrease after the total number reached the peak in 180 days.