腮腺主导管结扎及再通后腺泡凋亡与再生变化规律的研究

Roles of Apoptosis and Mitosis in the Regeneration of Rat Parotid Gland following Ligation-induced Atrophy

目的:研究大鼠腮腺主导管结扎及再通后腺泡凋亡与再生的变化规律。方法:通过对大鼠右侧腮腺主导管双重结扎14d后再通,建立腮腺组织萎缩后再生模型。分别于主导管再通术后0、1、3、5、7、10、14和21d获取腮腺组织标本,应用HE和AB-PAS染色观察腺体的组织学变化,免疫组织化学染色法检测腺泡中增殖细胞核抗原(PCNA)、半胱氨酸天冬氨酸蛋白水解酶3(Caspase3)的表达。结果:组织学观察见:主导管结扎14d后腺泡萎缩、消失,导管样结构增多,酶原颗粒消失;主导管再通术后,腺泡再生,导管样结构减少,酶原颗粒数目恢复正常。免疫组织化学染色分析结果示:在主导管结扎14d后PCNA散在表达,主导管再通1d后表达增加,5d后达峰值,7d后降低并趋于平稳;主导管结扎14d及再通后Caspase3表达水平持续较低,且平稳。各实验组间PCNA表达差异有统计学意义(P<0.05),而Caspase3表达差异无统计学意义。结论:腮腺主导管持续结扎14d后再通,萎缩的腺泡可再生,形态及功能均可恢复正常水平,表明主导管持续结扎14d对腺体组织造成的损伤完全可逆。

Objective：To investigate the roles of apoptosis and mitosis in the regeneration of rat parotid gland following release from duct ligation.Methods：The excretory duct was double ligated with metal-clip unilaterally near the hilum in order to induce atrophy of the parotid gland,and after 2weeks of ligation（day 0）the double-ligated duct was reopened from 0to 21 days in order to enable parotid gland regeneration.The evolving gland were examined with HE-staining,AB-PAS staining technique and immunohistochemistry for proliferating cell nuclear antigen（PCNA）as a marker of proliferating cells and Caspase3 as a marker of apoptotic cells.Results：After 14 days ligation,the vast majority of acinus and the zymogen granules were replaced by the ductal structure.But during the regeneration of parotid gland,many residual and newly formed acinar cells were identified by HE and AB-PAS staining accompanying increasing zymogen granules.There were occasional PCNA-positive acinar or duct cells in ligated gland,but after 3dof the release of metal-clip,many PCNA-positive cells were seen especially acinar cells between 3dto 7d,thereafter PCNA-positive cells decreased in number.During the regeneration of parotid glands,the Caspase3-positive cells were very rarely observed in 0d,but Caspase3-positive numbers decreased after that.The difference of PCNA-positive numbers were statistically significant between each group（P〈0.05）and the reaction of acinar cells compared to duct cells were significantly different at each point of the experimental group（P〈0.05）.Conclusion：During regeneration of the parotid gland,most acinar cells regeneration from the residual acinar cells at the peripheral region of lobules and the apoptosis of did not play important roles in the regeneration of rat parotid gland after 2weeks duct-ligation.