糖尿病大鼠胃肠功能紊乱时结肠组织中Cajal间质细胞的表达

The effect of interstitial cells of Cajal on pathogenesis of gastrointestinal dysfunction in rats with diabetes mellitus

目的观察糖尿病大鼠胃肠功能紊乱时结肠组织内Cajal间质细胞的分布及表达变化,探讨Cajal间质细胞在糖尿病胃肠功能紊乱发病机制中的作用。方法30只SD大鼠随机分为两组,糖尿病组20只,正常对照组10只。糖尿病组大鼠用链脲佐菌素单剂量腹腔注射建立糖尿病模型,对照组注射等量枸橼酸缓冲液。两组大鼠饲养6周后处死,计算胃肠推进率并且收集结肠组织标本。用免疫组化方法观察Cajal间质细胞在两组大鼠结肠组织内的分布和表达,用W estern b lot方法检测c-k it蛋白在两组大鼠结肠内的表达。结果糖尿病组大鼠胃肠推进率较对照组明显降低(P<0.05)。免疫组化和W estern b lot检测都显示糖尿病大鼠结肠组织内Cajal间质细胞的表达较正常大鼠明显减少(P均<0.05)。结论糖尿病大鼠结肠组织内Cajal间质细胞表达减少,推测与糖尿病大鼠胃肠功能紊乱有一定相关性。

Objective To investigate the changes of the distribution and expression of interstitial cells of Cajal （ICC） in the colon tissue of diabetic rats with the gastrointestinal dysfunction. Methods Thirty SD rats were randomly divided into the normal control group （n = 10） and the diabetic model group （n = 20）. Rats in the diabetic model group were injected intraperitoneally with streptozotocin （STZ） （80 mg/kg） for only one time, and rats in normal control group were intraperitoneally injected with the equal Citric Acid buffer. After 6 weeks, rats were sacrificed and colon tis- sues were collected. The distribution and expression of ICC in the proximal and distal colon tissue of rats in both groups were detected by immunohistochemistry; the expression of c-kit protein in the proximal and distal colon tissue of rats in both groups was detected by Western blot analysis. Results The immunoreaction positive products of ICC mainly dis- tributed in the myenteric plexus of the colon tissue. The expression of ICC in the proximal and distal colon tissue of diabetic rats decreased compared with that in control group （P 〈 0. 05）. Conclusion Decreased expression of ICC in the colon tissue might play an important role in the gastrointestinal dysfunction associated with diabetes mellitus.