不同冷保存时间对大鼠移植小肠形态学改变及对移植术后受体存活的影响

目的研究不同冷保存时间对大鼠移植肠所致的形态学改变,以及对移植术后受体存活的影响。方法SD大鼠随机分成对照组(假手术组,L组,n=6)、冷缺血3h组(L3组,n=6)、冷缺血6h组(L6组,n=6)、冷缺血12h组(L12组,n=6)、冷缺血18h组(L18组,n=6)。建立大鼠原位节段性小肠移植模型。各组热缺血时间均为2-3min,除对照组外其余各组按相应时间在乳酸林格液中进行冷保存(4℃),再灌注后1h取材。HE染色及电镜下观察小肠组织的损伤,并记录各组大鼠生存时间。结果HE染色下各组小肠均有不同程度的损伤,如出现不同程度的绒毛缩短、绒毛脱落;黏膜层变薄,肌层水肿增厚;基质层断裂等,这些损伤随保存时间延长而加重。电镜下表现为:小肠微绒毛排列不整齐,随着冷缺血时间延长,微绒毛出现脱落;线粒体、肌细胞逐渐出现水肿;血管内皮CAP窗孔增大;小肠上皮基质层断裂;此外,在L12组出现凋亡小体,L18组凋亡小体明显增多。术后生存分析显示:随冷保存时间增长,移植术后大鼠存活率下降(P<0.05)。结论供肠在乳酸林格液中保存,冷保存时间在6h以内最适于小肠移植;保存超过18h则不适于作小肠移植供体。

The effects of different cold preservation times of transplanted small intestine on histological change and survival of recipients in rats

Objective To investigate the effects of different cold preservation times of transplanted small intestine on histological change and recipient survival in rats. Methods SD rats were randomly divided into groups L, L3, L6, L12 and L18, with 6 in each. L: sham-operation group; L3: cold preservation time of 3 hours; L6: cold preservation time of 6 hours; L12: cold preservation time of 12 hours; L18: cold preservation time of 18 hours. Orthotopic small bowel transplantation model was established. The warm ischemia time was 2-3 minutes in all groups. Except the sham-operation group, all the rest groups were processed for the corresponding cold preservation time (4℃), respectively. The samples were obtained from the different groups for histological examination after reperfusion for 1 hour. The survival time was recorded. Results By HE staining, each group was histologically injuried in different degree. For in stance, villi were shortened and had abscission; mucous membranes became thin, myometrium had edema and thickened; the epithelial basement membrane was disrupted. Under transmission electron microscope, microvilli lined up out of order. With cold preservation time increasing, the microvilli had abscission, muscle cells and mitochondria had edema, blood vessel endothelium CAP window was enlarged, the epithelial basement membrane was disrupted. In the L12 group, the apoptotic body appeared, while in the L18 group, the quantity of apoptotic body increased obviously. The survival analysis showed that as the time of cold preservation increased, the survival rate of rats after intestinal transplantation decreased (P<0.05). Conclusion Small intestine preserved for a period of 6 hours in Ringer lactate solution is suitable for transplantation while preservation time more than 18 hours is unsuitable.