BALB/c小鼠溃疡性结肠炎远段结肠Cajal间质细胞超微结构变化

Changes of Ultrastructure of Cajal Interstitial Cells in Distal Colon of BALB/c Mice with Ulcerative Colitis

目的观察急慢性溃疡性结肠炎(UC)小鼠远段结肠组织Cajal间质细胞(ICC)超微结构变化,探讨ICC在UC肠功能紊乱发病中的作用。方法将30只BALB/c小鼠随机分为健康对照组、急性UC和慢性UC组,每组10只。通过饮用50 g/L葡聚糖硫酸钠(DSS)法建立BALB/c小鼠急、慢性UC动物模型,将仅饮用蒸馏水的BALB/c小鼠作为对照组。分别取3组小鼠远段结肠组织标本,固定、脱水、包埋,常规超薄切片,硝酸铅、醋酸铀染色,JEM-2000EX透射电子显微镜观察。采用SPSS 11.6软件进行统计学处理。结果1.健康对照组BALB/c小鼠远段结肠ICC超微结构主要特点:细胞呈纺锤形,有巨大的卵圆形核及向外伸展的长突起,胞质内有丰富的线粒体、大量光面和粗面内质网;环肌层和纵肌层ICC与肠神经元及平滑肌细胞之间联系密切。2.急性UC组小鼠远段结肠ICC超微结构改变:细胞体积增大;线粒体肿胀、电子密度降低,部分线粒体空泡样变;溶酶体数目增多,出现次级溶酶体;部分ICC胞质内可见大量脂滴;黏膜下层(IC-SM)周围出现大量巨噬细胞。3.慢性UC组小鼠远段结肠ICC超微结构改变:细胞形态基本正常,线粒体形态基本正常或轻度肿胀,溶酶体数目增多,以初级溶酶体为主;IC-SM周围巨噬细胞数目较少。结论UC小鼠远段结肠组织ICC超微结构发生改变,这些结构改变与其功能改变密切相关,推测与UC小鼠肠功能紊乱有一定相关性。

Objective To explore the changes of uhrastructure of interstitial cells of Cajal（ICC） in distal colon and gastrointestinal dysfunction, and the role of ICC in acute and chronic ulcerative colitis （ UC ）. Methods Thirty BALB/c mice were randomly divided into 3 groups. The experimental groups were fed with 50 g/L dextran sulfate sodium （DSS） solution for 7 days and 50 g/L DSS solution for 7 days followed by distilled water for 14 days to induce acute and chronic UC ,respectively. The control group were only fed with distilled water. Samples were selected from the distal colon of 3 groups respectively, then fixation, dehydration, embedding slicing and staining. The changes of ultrastructure characteristics of ICC in distal colon were observed by using JEM -2000EX transmission electron microscope （TEM）. SPSS 11.6 software was used to analyze the data. Results 1. In control group,ICC were characterized by long process,large oval nuclei and scant perinuclear cytoplasm. The cytoplasm contained numerous mitochondria, aboundant smooth and rough endoplasmic reticulum. ICC in the circular muscle layer and longitudinal muscle layer of BALB/c mice colon had close relationship with enteric neuron and smooth muscle cells. 2. In the acute UC group,the volume of ICC were increased. The mitochondria were swollen and their density were lower. The numbers of lysosomes were increased and often showed multiple secondary lysosomes. Large confluent lipid bodies were often found in cytoplasm. Macrophages were frequently appeared around submucosal plexus ICC （IC -SM）. 3. In the chronic UC group, the configuration of ICC was normal. The mitochondria was normal or swollen mildly. The numbers of lysosomes were increased and mainly showed primary lysosomes. Macrophages were obviously decreased around IC - SM. Conclusions The nltrastructure of ICC had distinct changes, these changes were closely related with the changes of their function. Accordingly ,these changes in ICC in the distal colon may play an important role in gastrointestinal dysfunction associated with UC.