大鼠胃黏膜电切术后局部T细胞亚群的变化

The Changes of T Lymphocyte Subsets in Local Tissue of Gastric Mucosal Electrocision in Rats

目的通过对大鼠胃黏膜电切术后创面局部胃壁组织T淋巴细胞亚群相应指标的测定,旨在探讨细胞免疫在大鼠胃溃疡局部黏膜组织间的发生及变化。方法选取54只成年健康SD大鼠随机分为3组:正常对照组、假手术组(分为1周、2周、3周和4周4个时间段小组)和手术组(分为溃疡组1周、溃疡组2周、溃疡组3周和溃疡组4周4个时间段小组)。除正常对照组外,其余各组动物均接受剖腹手术,通过单极电刀在胃窦前壁做小切口行胃窦黏膜电切术,将手术组及假手术组分别于术后第1、2、3、4周用断头法处死,正常组不做特殊处理,适应性喂养1周后处死。留取电切术后溃疡局部胃壁组织行常规脱水、石蜡包埋。用ABC免疫方法进行CD3、CD4、CD8、IFN-γ和CD177指标免疫组化染色,用图像分析法测定阳性表达部位的积分光密度值(IOD),并计算平均光密度值(MOD)。结果手术组、假手术组及正常组大鼠胃组织中均有CD3、CD4、CD8、IFN-γ和CD177表达。阳性染色主要显色于黏膜的上皮层和固有层中,少数也显色于黏膜下层中。电切术后CD3、CD4在手术组各时间段胃溃疡局部组织的MOD较对照组和正常组均减少(P<0.05),手术组内各时间段之间没有差异(P>0.05)。各组之间、各时间段之间的CD8均没有差异(P>0.05),电切术后CD177和IFN-γ在手术组各时间段胃溃疡局部组织的MOD较假手术组和正常组均增多(P<0.05),手术组各时间段之间没有差异(P>0.05)。结论大鼠经胃黏膜电切术后至少4周内,局部均存在急性炎症反应;局部T细胞亚群异常,以CD4+T细胞数量的减少为主,伴有IFN-γ和CD177的升高,这种改变引起的可能主要是体液免疫的进一步变化。

Objective To investigate the changes of T lymphocyte subsets in local tissue of gastric mucosal electrocision in rats. Methods 54 SD rats were randomly divided into three groups： normal control group, sham operation group （was divided into 1st week, 2nd week, 3rd week and 4th week subgroup） and surgical group （was divided into ulcer group 1st week, ulcer group 2nd week, ulcer group 3rd week and ulcer group 4th week subgroup）. All rats in each group except normal control underwent laparotomy and gastrotomy. And each rat in electrocision group received mucosal electrocision at gastric antrum additionally. Every 6 rats were executed at the 1st, 2nd, 3rd and 4th weekend in sham group and electrocision group. The rats in normal control group were executed after one week adaptive feeding. Tissue simples at the mucosal electrocision site of gastric antrum in electrocision group, and those at the similar site of gastric antrum in sham group and normal control group, were prepared for paraffin section which was used to detect CD3, CD4, CD8, IFN-γ and CD177 by immunohistochemistry and image analysis. Results The positive staining was mainly located in the gastric mucosa epithelium layer and lamina propria; the light positive staining was found in the submucosa in all groups. The MOD of CD3 and CD4 in surgery group were lower than those in sham operation group and in normal control group （P 0.05）. There was no difference among each time points of subgroup in surgery group （P 0.05）, and no difference of CD8 was found among each subgroup in surgery group （P 0.05）. The MOD of IFN-γ and CD177 in surgery group were lower than those in sham operation group and normal control group （P 0.05）. Conclusions Acute inflammatory reaction in the site of mucosal electrocision lasts for at least 4 weeks. T cell subset is abnormal only with the decreased number of CD4＋ T cells. Increased IFN-γ, T cell subsets abnormality and increased CD177 may principally make some changes in humoral immunity.