血小板活化因子对幼鼠肠道免疫屏障功能的影响

Effect of platelet activating factor on function of intestinal immunological barrier in young rats

目的:探讨血小板活化因子(plateletactivatingfactor,PAF)对肠黏膜分泌型IgA(secretoryIgA,SIgA)的影响.方法:用50μg/kg和65μg/kgPAF对大鼠进行腹腔注射(1μL/g),不同时间点处死动物,应用双抗体-PEG放射免疫法测定肠黏膜中SIgA含量,常规苏木精-伊红染色,光镜观察形态学改变.结果:PAF65组回肠0.5,1.5,3h可见绒毛水肿,固有层血管充血,间质淋巴管扩张,肠腔炎性渗出,上皮脱落,6,24h绒毛水肿.PAF50组0.5,1.5h可见绒毛水肿,固有层血管充血,3,6,24h绒毛水肿.实验组0.5,1.5,3,6hSIgA均较对照组显著降低(PAF50组分别为0.31±0.03mg/L,0.40±0.10mg/L,P<0.01,0.43±0.13mg/L,0.46±0.11mg/L,P<0.05;PAF65组分别为0.28±0.07mg/L,0.36±0.08mg/L,P<0.01,0.40±0.11mg/L,0.42±0.06mg/L,P<0.05vs0.66±0.10mg/L).0.5h下降幅度最大,随时间推移有逐渐升高趋势.结论:PAF可损害肠黏膜的免疫屏障功能,使SIgA降低.

AIM： To investigate the effect of platelet activating factor （PAF） on the content of secretory IgA （SIgA） in intestinal mucosa. METHODS： The rats were intraperitoneally injected with different concentrations of PAF （50 and 65 μg/kg） at a dose of 1 μL/g. Double antibody-PEG radioimmunoassay was used to determine the amount of SIgA in the intestinal mucosa. The histological changes were detected by hematoxylin and Eosin staining under light microscope. RESULTS： In the PAF65 group, the histological exami- nation showed edema of the villus, capillary congestion of the lamina propria, extension of the subepithelial lymphatic channel, polymorphonuclear infiltration in enteric cavity, and shedding of the epithelial layer at 0.5, 1.5, and 3 h. Edema of the villus were still shown at 6 and 24 h. In the PAF50 group, edema of the villus, capillary congestion of the lamina propria were showed at 0.5 and 1.5 h. Edema of the villus were still shown at 3, 6 and 24 h. The content of SIgA was obviously decreased in the experimental group than that in the control group （0.31±0.03 mg/L, 0.40±0.10 mg/L, P 〈0.01; 0.43±0.13 mg/L, 0.46±0.11mg/L, P 〈0.05, in PAFso group; 0.28±0.07 mg/L, 0.36±0.08 mg/L, P 〈0.01, 0.40±0.11 mg/L, 0.42±0.06 mg/L, P 〈0.05, in PAF6s group vs 0.66±0.10 mg/L in the control） at 0.5, 1.5, 3 and 6 h, respectively. The SIgA content decreased most at 0.5 h, but then gradually increased. CONCLUSION： PAF can lead to damages of the intestinal immunologic barrier by decreasing the SIgA content.