硝普钠对大鼠植入小肠黏膜屏障的保护机制

Protective mechanism of sodium nitroprusside on mucosal barrier of transplanted intestine in rat segmental heterotopic segmental bowel transplantation model

目的:探讨硝普钠(SNP)对移植小肠黏膜屏障的保护机制。方法:以单袖套法构建SD大鼠节段小肠移植模型为研究对象,用硝普钠作为外源性一氧化氮(NO)供体,分成缺血再灌注(I/R)前SNP注射组(A1)、SNP灌注组(A2)、I/R后SNP注射组(A3)与对照组(不用SNP组),观察受体植入肠造口变化情况,并获取植入肠标本,检测黏膜Na+-K+-ATP酶及细胞凋亡情况,初步分析SNP在不同干预时机对植入小肠黏膜的保护机制。结果:A1、A2组较对照组造口坏死及不良发生率低(P<0.05)、移植肠及受体生存率高(P<0.05)、黏膜组织Na+-K+-ATP酶含量高(P<0.05)、黏膜上皮及腺上皮细胞凋亡指数降低(P<0.05)。其中A2组以上各指标差异最明显,A3组以上指标均与C组无显著性差异(P>0.05)。结论:利用外源性NO供体SNP进行供肠I/R前预处理与灌注,能够提高大鼠植入肠黏膜屏障的结构和功能完整,而I/R后注射SNP是无效的。

Objective To investigate the protective mechanism of nitrogen monoxidum（NO） donor on the mucosal barrier of transplanted intestine. Methods Reconstruction of the segmental bowel transplantation（SBT） model and the whole series was divided at random into four groups. In group 4 （n=12）, the control group, SBT was performed without previous SNP treatment. In Group A1 （n=8）, the process was preconditioned with SNP before graft I/R and SBT.In Group A2 （n=7）, while harvesting the graft,it was first flushed with SNP and then performed the SBT. In Group A3 （n=12）, SNP was flushed after the SBT. In all groups,the condition of the stoma was carefully observed and a sample of the stoma was taken for further detecting the Na^＋-K^＋-ATPase of the intestinal mucosal tissue and apoptosis. Results There were a lower degree of stomal necrosis （P〈0.05）, a higher percentage of graft and recipient survival rate （P〈0.05）, a higher quantity of Na^＋-K^＋-ATPase in the graft mucosal tissue （P〈0.05） and a lower rate of apoptosis among the mucosal epithelial cells of the graft in Groups A1 and A2 than that in the control group （P〈0.05）. The most obvious protective effect was observed in Group A2 （SNP flushed group） and no significant difference was noted between Groups A3 and the control. Conclusions SNP given before ischemia and used as a flushing agent produces reliable effect on the structural and functional integrity of the mucosal barrier of the transplanted intestine,but no effect is witnessed when given after I/R.