重症胰腺炎大鼠肠道免疫功能改变及精氨酸的调节作用

Alterations of intestinal immune function and regulatory effects of L-arginine in rats with experimental severe acute pancreatitis

目的:探讨重症急性胰腺炎(SevereAcutePancreatitis,SAP)大鼠肠道黏膜免疫功能变化及L精氨酸(LArg)对SAP大鼠肠道黏膜免疫功能的影响。方法:成年、雄性Wistar大鼠随机分为胰腺炎组、假手术组和L精氨酸治疗组。分别于造模后24、48和72小时取标本检测:鲎试剂法检测大鼠门静脉血内毒素水平、免疫组化方法检测并计数小肠黏膜固有层内CD3、CD4、CD8阳性T淋巴细胞百分数、放射免疫法检测盲肠内容物中分泌型IgA(SIgA)含量。结果:SAP组大鼠各时段门静脉血内毒素水平显著升高,回肠末段黏膜固有层CD3+、CD4+T淋巴细胞百分数明显减少,CD4+/CD8+T淋巴细胞比值降低,盲肠内容物SIgA含量明显降低;与SAP组比较,L精氨酸组大鼠各时段门静脉血内毒素水平明显降低,回肠末段黏膜固有层CD3+、CD4+T淋巴细胞百分数明显增加,CD4+/CD8+T淋巴细胞数比值升高,盲肠内容物SIgA含量增加。结论:SAP大鼠早期即发生肠黏膜免疫功能明显下降,可能是导致肠道内毒素移位的主要原因,L精氨酸可以改善SAP大鼠肠道黏膜免疫功能,降低SAP大鼠肠道内毒素移位发生。

Objective：To discuss the changes of intestinal mucosal immune function in experimental severe acute pancreatitis （SAP） rats and the regulatory effect of L-arginine. Methods： Male adult Wistar rats were randomly divided into pancreatitis group, sham-operation group and L-arginine treatment group. Animals were sacrificed at 24, 48 and 72 h after SAP models were developed and specimens were harvested. Endotoxin concentration in portal vein was determined by limulus endotoxin analysis kit. CD3 ^＋CD4^＋ , CD8 ^＋ T lymphocytes in intestinal mucosal lamina propria were examined by immunohistochemistry. Secretory immunoglobulin A （SIgA） in cecum feces was examined by radioimmunoassay. Results：Compared to the control group, plasma endotoxin concentration in the portal increased, percentage of CD3 ^＋ and CD4 ＋ T lymphocyte subsets in the end of intestinal mucosal lamina propria reduced significantly, CD4^＋/CD8^＋ ratio decreased, and SIgA concentrations in cecum feces reduced at 24,48 and 72 h after SAP developed. Compared to SAP group, the L-arginine treatment group had a lower level of plasma endotoxin concentration in the portal vein, a higher CD3^＋ and CD4^＋T lymphocyte percentage in the end of intestinal mucosal lamina propria, an increased ratio of CD4^＋/CD8 ^＋ and a higher SIgA concentration in cecum feces. Conclusion：Intestinal immune suppression occurs in the early stage of SAP rats, which may be the main reason for bacterial and endotoxin translocation. L-arginine can improve the intestinal immunity and reduce bacterial and endotoxin transloeation in SAP rats.