小剂量FK506预处理对大鼠小肠移植缺血再灌注损伤中细胞凋亡的影响

Effects of low-dose FK506 preconditioning on cell apoptosis during ischemia/reperfusion injury caused by small bowel transplantation in rat

目的 :研究小剂量FK5 0 6预处理对大鼠小肠移植缺血再灌注 (ischemia/reperfusion ,I/R)损伤中细胞凋亡的影响 .方法 :建立大鼠小肠移植I/R损伤模型 ,FK5 0 6预处理方式为大鼠浅麻醉后按 0 .3mg·kg-1 剂量通过尾静脉注射 ,自然环境恢复 6h后行异位节段性小肠移植术 ;免疫荧光细胞化学方法检测移植肠凋亡细胞 ;免疫组化方法测定移植肠中热休克蛋白 70 (HSP70 )表达 .结果 :小肠移植I/R损伤造成小肠粘膜细胞凋亡增加 ,小剂量FK5 0 6预处理可有效减少I/R损伤引起的细胞凋亡 ,荧光强度定量分析表明 ,同虚假手术组相比 ,I/R组各时相点荧光强度明显增强 (0 .5 ,6 .0 ,2 4 .0h ,P<0 .0 1 ) ;FK5 0 6预处理组各时相点荧光强度与I/R组相比明显减少 (0 .5h ,P <0 .0 5 ;6 .0h ,P <0 .0 5 ;2 4 .0h ,P <0 .0 1 ) ;虚假手术组无HSP70表达 ,I/R组再灌注后 0 .5和 6 .0h未见HSP70表达 ,2 4 .0h可见有少量HSP70表达 ,FK5 0 6预处理组再灌注后 0 .5h即可见有少量HSP70表达 ,6 .0h时表达增多 ,再灌注后 2 4 .0h ,HSP70表达至高峰 .结论 :小剂量FK5 0 6预处理可有效减少I/R引起的细胞凋亡 ,减轻大鼠移植肠的缺血再灌注损害 ;

AIM: To study the effects of low dose FK506 preconditioning on the cell apoptosis during the ischemia/reperfusion injury caused by small bowel transplantation in rat. METHODS: The model of ischemia/reperfusion injury was established in rat with small bowel transplantation. Rats were pretreated with FK506 (0.3 mg·kg -1 , iv) through the tail vein after the rats were slightly anesthetized and 6.0 h after they were recovered in natural condition, small bowel transplantation was performed. The apoptotic cells were detected using immunofluorescence cytochemistry technology. Immunohistochemistry method was used to assay the expression the HSP70. RESULTS: Ischemia/reperfusion injury resulted in an increase of apoptotic cells in intestinal mucosa. Low dose FK506 preconditioning significantly decreased the apoptotic cells. Immunofluorescence analysis showed that fluorescence intensity in I/R group increased at each time point compared with that in the sham group(0.5 h, 6.0 h, 24.0 h, P <0.01 versus sham group). Low dose FK506 preconditioning significantly decreased the fluorescence intensity (0.5 h, P <0.05; 6.0 h, P <0.05; 24.0 h, P <0.01 versus I/R group). There is no expression of HSP70 in sham group. The faint expression of hsp70 can be seen at 24.0 h after reperfusion in I/R group. In FK506 group, the expression of HSP70 appeared at 0.5 h after reperfusion, increased at 6.0 h and achieved the peak expression at 24.0 h. CONCLUSION: Ischemia/reperfusion injury in rat with small bowel transplantation can induce the intestinal mucosa cells apoptosis. Low dose FK506 preconditioning significantly decreases the apoptotic cells and reduces the I/R injury. This protective effect may be related to the induction of hsp70.