胰岛素对2型糖尿病患者结肠Cajal间质细胞及乙酰胆碱变化的影响

目的 比较接受不同治疗的2型糖尿病患者与非糖尿病对照的结肠cajal间质细胞(ICC)及乙酰胆碱(Ach)的形态、分布及数量,了解糖尿病患者结肠ICC及Ach的变化以及胰岛素治疗对其的影响.方法 取结肠癌手术标本切缘的正常结肠组织共81例,其中非糖尿病对照29例,2型糖尿病52例(胰岛素治疗24例,口服降糖药治疗28例).免疫组化检测c-kit阳性细胞及Ach表达;甲苯胺蓝染色肥大细胞. c-kit阳性细胞与肥大细胞数之差为ICC数目,图像处理软件分析Ach表达及密度.结果 结肠的黏膜下层、环行肌及纵行肌层内(IM)、肌间(MY)神经丛均有c-kit阳性细胞分布.糖尿病患者的ICC细胞突起明显减少、分布松散,较多空泡形成,这些变化在口服降糖药组更明显.ICC数目比较:对照组>胰岛素组>口服降糖药组(ICC-MY:60.12比23.95比16.49, P=0.000; ICC.IM:41.79比33.18比25.88, P=0.000).结肠黏膜下神经丛和肌间神经丛均有Ach表达,糖尿病患者Ach阳性细胞分布松散,较多空泡形成,口服降糖药组更明显. Ach阳性表达分析,面密度:对照组>胰岛素组>口服降糖药组(147.50比103.82比86.38, P=0.000).对非糖尿病对照组的分析表明,ICC数目及Ach表达与年龄、性别无相关性.结论 糖尿病患者结肠ICC及Ach较对照组分布松散,较多空泡形成,ICC数量及Ach表达明显减少.胰岛素对上述变化具有保护作用.结肠ICC数目及Ach表达与年龄及性别无关.

Insulin protects the loss of colonic interstitial cells of Cajal and acetylchofine in patients with type 2 diabetes mellitus

Objective A deficiency of interstitial cells of Cajal (ICC) and neuronal nitric oxide synthase (nNOS) in the gastrointestinal muscle layer have been shown in both diabetic animal models and patients with diabetes mellitus (DM), but little is known about the alteration of colonic acetylcholine (Ach) expression in patients with DM. and it is remain unclear whether those changes are related to different treatments. This study examined whether the ICC density, or the expression of Ach containing nerves in the colon, was altered in patients with type 2 DM, and whether those changes were protected by insulin treatment. Methods Paraffin embedded colonic specimens that have been fixed in 10% formalin were collected from 8l patients with colon cancer who underwent colectomy (non-DM as controls, M/F=17/12;DM with insulin treatment. M/F=12/12; DM with oral medication treatment, M/F=19/9). Serial sections were stained with antibodies to c-kit and Ach using immunohistochemical method. Meanwhile, mast cells were stained with toluidine blue. The ICC number was calculated by subtraction of the number of mast cells from the number of c-kit positive cells. The number of ICC and the expression of Ach were compared among the controls and DM patients with different treatment. Results C-kit positive cells, which located within the inner muscle layer and muscular plexus mainly, were expressed in control group and they were much more regular and less vacuolization than that of controls. The density of both intramuscular-ICC (ICC-IM) and myenteric ICC (ICC-MY) were much lower in patients with DM than that in the controls. Furthermore, ICC density in DM patients who underwent insulin treatment was higher than that in patients with oral medical therapy (control vs insulin vs oral medication group:ICC-MY, 60.12 vs 23.95 vs 16.49, P=0.000; ICC-IM,41.79 vs 33.18 V8 25.88, P=0.000). In addition, the alteration of Ach expression in colonic enteric nerves was similar as the pattern of ICC (control vs insulin vs oral medication group:147.50 vs 103.82 vs 86.38, P:0.000). There was no influence of gender and age to the alteration of ICC and Ach. Conclusions The colonic ICC and Ach in DM patients is irregular. and the distribution is loose. with lots of vacuolization. The density of clonic ICC-IM and ICC-MY were lower in DM patients than that in controls accompanied with downregulation of enteric nerves Ach expression. These alterations could be protected by insulin treatment.