急性肠缺血状态下I-FABP表达及诊断意义的实验研究

摘要

目的: 在急性肠缺血不同时间段,检测I-FABP在肠组织中的表达和分布及其血清浓度的变化,并探讨I-FABP在急性缺血性肠病早期诊断中的意义和机制.方法: 选取健康成年SD大鼠96只,随机分为实验组和对照组,每组48只,两组内再随机分成6小组,每组8只.实验组结扎肠系膜上动脉,对照组仅行腹腔开关术.各小组大鼠分别对应在手术后0.5 h,1 h,2 h,4 h,8 h,12 h从右心室中抽取静脉血检测I-FABP浓度,其后处死大鼠,切取病变肠管制成石蜡切片,行常规HE染色及运用直接免疫荧光染色法对肠组织中I-FABP进行染色.结果: I-FABP主要表达在肠粘膜上皮绒毛,肠粘膜下层、甚至肌层也有少量的表达.在肠缺血1 h内,肠管及肠腔内I-FABP阳性颗粒数逐渐增多,1 h后逐渐下降,各实验组和对照组相比,差异有统计学意义(P＜0.05).血清I-FABP: 实验组在肠缺血0.5 h开始升高,1 h达峰值(290.24±156.69)μg·L-1 ,之后逐渐下降,与对照组相比,差异有统计学意义(P＜0.05).结论: I-FABP平时主要存在于肠粘膜上皮细胞中,急性缺血时,肠粘膜上皮细胞的通透性发生改变,I-FABP迅速表达释放至肠壁组织和肠腔内,并被吸收至血液中.因此,血清I-FABP对急性肠缺血的早期诊断及治疗有一定的临床意义.%Objective: To detect the expression and distribution of I-FABP in intestinal tissues and the changes of serum concentrations at different time of acute intestinal ischemia, and explore the significance and mechanism of I-FABP in early diagnosis of acute ischemic bowel disease. Methods: The selected 96 healthy adult SD rats were randomly divided into experimental group and control group; 48 in each group. Each group was randomly subdivided into 6 groups with 8 rats in each group. The superior mesenteric artery was ligated in the experimental group and the peritoneal switch operation was performed in the control group. The venous blood samples were extracted from each group rats' right ventricle at0. 5 h, 1 h, 2 h, 4 h, 8 h, 12 h after the operation and the concentration of I-FABP was tested respectively. Then the rats were killed, and the diseased intestinal tubes were cut out for paraffin sections. The I-FABP in intestinal tissues was stained by routine HE staining and direct immunofluorescence staining. Results: The I-FABP was mainly expressed in the epithelial villi of intestinal mucosa, and there was a small amount of expression in the intestinal submucosa and even the muscularis. Within 1 hour of intestinal ischemia, the number of I-FABP positive granules in the intestine and intestinal cavity increased gradually, and then gradually decreased after 1 hour, The difference has statistically significant between the experimental group and the control group (P＜ 0. 05). The serum I-FABP: In experimental group, the serum IFABP concentration began to increase at 0. 5 h, and reached a peak at 1 h(290. 24 ± 156. 69) μg·L-1, then gradually decreased. Compared with the control group, the difference was statistically significant (P＜ 0. 05). Conclusion: IFABP usually mainly exists in the epithelial cells of intestinal mucosa. When acute intestinal ischemia occurs, the epithelial cells of intestinal mucosa permeability changes; I-FABP expression rapidly releases to intestinal tissue and intestinal cavity, and is absorbed into the blood. Therefore, I-FABP has certain clinical significance in early diagnosis and treatment of acute intestinal ischemia.