摘要目的 观察新生大鼠肠道组织中肠型脂肪酸结合蛋白(intestinal fatty acidbinding protein,I-FABP)的表达情况,探讨I-FABP与新生儿坏死性小肠结肠炎(necrotizing enterocolitis,NEC)的相关性. 方法 24只2日龄无特定病原体级新生Sprague-Dawley大鼠随机分为空白对照组(6只)和NEC模型组(18只).通过连续3d人工喂养+缺氧复氧+冷刺激+脂多糖灌胃(10 mg/kg)建立NEC模型,分别在造模成功后第1、2、3天随机选取6只大鼠空腹处死;空白对照组于NEC模型组造模成功后第3天空腹处死.处死后取大鼠回盲部肠管行组织病理评分,以及采用蛋白质印迹技术及免疫组织化学法检测回盲部肠组织I-FABP蛋白表达情况.采用单因素方差分析、LSD-t检验、Kruskal-Wallis H秩和检验、Mann-Whitney U检验,以及Pearson相关分析进行统计学分析. 结果NEC模型组大鼠全部顺利完成造模,造模过程中并无死亡,且肠组织病理学评分均≥2分,造模成功.NEC模型组造模后第1、2、3天体重增加[M(P25～P75)]均低于空白对照组[分别为1.00(0.48～1.35)与1.74(1.62～1.86)g,1.25(0.75～1.40)与2.61 (2.53～2.99)g,1.35 (0.88～1.48)与3.60(3.48～3.73)g,Z值分别为-2.898、-2.903及-2.892,P值均＜ 0.05],但肠组织病理学评分均高于空白对照组[分别为2(2～3)、3(2～3)、4(3～4)与0(0～1)分,P值均＜ 0.05],而NEC模型组造模后第3天大鼠肠组织病理评分显著高于造模后第1及第2天(P值均＜ 0.05).NEC模型组造模后第1、2、3天大鼠肠组织I-FABP表达水平及I-FABP阳性细胞数均高于空白对照组[I-FABP表达水平:0.179 (0.179～0.186)、0.231 (0.211～0.245)、0.202(0.192～0.225)与0.091(0.086～0.093);I-FABP阳性细胞数:59 (55～60)、80(83～86)、80(84～88)与44(39～47)个;P值均＜0.05],与造模后第1天相比,NEC模型组造模后第2及3天大鼠肠组织I-FABP表达水平及I-FABP阳性细胞数均较高(P值均＜0.05).蛋白质印迹技术与免疫组织化学法检测肠道组织I-FABP表达水平与肠道组织病理评分均呈正相关(r=0.932,95％CI:0.872～0.969;r=0.709,95％CI:0.484～0.872). 结论 I-FABP与NEC肠组织损伤程度存在相关性.

abstractsObjective To analyze the role of intestinal fatty acid-binding protein (I-FABP) expression in a neonatal rat model of necrotizing enterocolitis (NEC).Methods A total of 24 newborn rats were randomly divided into two groups:control group (n=6) and NEC group (n=18).Rats in the NEC group were fed with formula and experienced hypoxia,reoxygenation,cold stress and sequentially Lipopolysaccharide (10 mg/kg) lavage for three consecutive days to establish NEC model,after which were respectively sacrificed on day 1,2 and 3 (six for each day).Those in the control group were all sacrificed on day 3.Ileocecal tissues were collected for morphological and histological analysis.I-FABP expression was detected using Western blot and immunohistochemistry (IHC).One-way analysis of variance,LSD-t test,Kruskal-Wallis H test,Mann-Whitney U test and Pearson's correlation analysis were used for statistical analysis.Results The NEC model (intestinal pathological score ≥ 2) was established successfully without causing death.Compared with the control group,the NEC group showed less body weight gain [M (P25-P75):1.00 (0.48-1.35) vs 1.74 (1.62-1.86),1.25 (0.75-1.40) vs 2.61 (2.53-2.99),1.35 (0.88-1.48) vs 3.60 (3.48-3.73);Z=-2.898,-2.903,-2.892;all P＜0.05] and higher intestinal pathological scores [(2 (2-3),3 (2-3),4 (3-4) vs 0 (0-1);all P＜0.05] on day 1,2 and 3.The intestinal pathological score on day 3 was significantly higher than that on day 2 and day 1 (both P＜0.05).Expression of I-FABP and the number of I-FABP positive enterocytes in the NEC model group were increased compared with those in the control group [Western blot:0.179 (0.179-0.186),0.231 (0.211-0.245),0.202 (0.192-0.225) vs 0.091 (0.086-0.093);IHC:59 (55-60),80 (83-86),80 (84-88) vs 44 (39-47);all P＜0.05].Moreover,the expression of I-FABP protein and the number of I-FABP positive enterocytes on day 2 and day 3 were significantly higher than those on day 1 (all P＜0.05).I-FABP expression was positively associated with intestinal pathological score (Western blot:r=0.932,95％CI:0.872-0.969;IHC:r=0.709,95％CI:0.484-0.872).Conclusions I-FABP is an efficient marker for NEC and correlates with the severity of intestinal injury.