腮腺主导管结扎诱导萎缩后的组织转归

Changes of the atrophic parotid gland induced by duct ligation

背景:人体大唾液腺常因受到头颈部肿瘤放射治疗、舍格伦综合征及涎腺炎等因素的影响发生腺体萎缩,目前对长期萎缩性腮腺内组织形态变化的观察仍较少。目的:观察腮腺主导管结扎诱导腮腺萎缩后的组织转归。方法:通过结扎SD大鼠右侧腮腺主导管诱导腺体萎缩,采用苏木精-伊红染色观察正常腮腺及导管结扎后0(对照),1,3,7,14,30,60d萎缩性腮腺组织内腺泡、导管细胞的面积;免疫组织化学染色定量分析肌上皮细胞在腮腺萎缩不同时间点的数量分布变化。结果与结论:结扎腮腺主导管后腺泡细胞出现快速凋亡,至14d时已基本消失。随着腺体萎缩,间质逐渐纤维化并伴随炎性细胞浸润,组织内形成大量导管样结构,导管面积逐渐增加,到14d时达到顶峰,随后逐渐减少,导管样结构呈典型的双套层结构,结扎各时间点腺泡、导管面积与对照组比较差异均有显著性意义(P<0.05)。结扎后7d内肌上皮细胞数量快速增加,随后肌上皮细胞数量增长缓慢,维持在一定的范围。表明腮腺主导管结扎诱导腺体萎缩早期腺泡细胞快速消失,出现大量导管样结构,肌上皮反应性增殖,随着腺体的萎缩由导管样结构及肌上皮细胞组成"双套层"结构可能抑制腺体的进一步萎缩。

BACKGROUND：The human major salivary glands are usually affected by various factors,such as radiation therapy,Sjogren＇s syndrome and sialadenitis,which can lead to atrophy.At present,there are only few studies on the morphological changes of long-term atrophic parotid gland.OBJECTIVE：To investigate the changes of the atrophic parotid gland induced by its main duct ligation.METHODS：After the duct ligation of the atrophic parotid gland induced by its right main duct of SD rats,the area of inner acinar and duct cells of normal parotid gland and atrophic parotid gland tissues were examined by hematoxylin-eosin staining after duct ligation for 0（control）,1,3,7,14,30 and 60 days.Changes in number and distribution of myoepithelial cells in the atrophic parotid gland at different time points were analyzed by immunohistochemical staining method.RESULTS AND CONCLUSION：Morphological analysis showed that rapid apoptosis in the acinar cells appeared after the ligation of the main duct in the parotid gland,and cells almost disappeared at day 14.With the atrophy of the parotid gland,a gradual decrease and fibrosis of the glandular lobules with inflammatory cell infiltration appeared.And a number of duct-like structures formed.Besides,the area of duct was gradually increased,and then was gradually decreased after reaching the peak at day 14.Duct-like structures showed a classic double-layers structure.The areas of acinar and duct in the experimental group were significantly different from those in the control group（P0.05）.At day 7 after ligation,quantitative analysis showed significant increase in the number of myoepithelial cells,followed by gradual increases,which,however,were not statistically significant.These results suggest that in the earlier atrophic stage,there was a rapid disappearance of acinar accompanied by the occurrence of duct-like structures,and reactive myoepithelial cells proliferation.Ultimately,the ＂double-layers＂ structures composed by myoepithelial cells and duct-like structures may have great significances in the process of resisting atrophy.