人源化基因修饰猪血红细胞常温机械灌注技术对人断肢的保护作用

Protective effect of normothermic mechanical perfusion with red blood cells from humanized genetically modified pigs on severed human limb

目的探讨人源化基因修饰猪血红细胞常温机械灌注对人离断肢体的保存作用。方法采用人源化基因修饰猪血红细胞灌注人离断肢体6 h。每小时取灌注液检测血氧分压、Na^(+)、K^(+)、Ca^(2+)、pH值、葡萄糖、乳酸及肌酸激酶水平,取浅层屈肌检测肿瘤坏死因子(TNF)-α、白细胞介素(IL)-2、IL-1变化。灌注0 h、6 h取适量前臂浅层屈肌,进行病理学检查,观察骨骼肌细胞间隙及糖原消耗情况。每2 h取适量前臂血管,检测血管内皮细胞凋亡情况。灌注开始前及灌注6 h行X线造影,观察指端末梢血管充盈度。结果灌注过程中氧分压处于正常范围。Na^(+)在1 h出现高峰,达到138.7 mmol/L,之后波动于正常范围;K^(+)在2 h出现高峰,为6.08 mmol/L,之后下降,波动于正常范围;Ca^(2+)在4 h达高峰,为1.03 mmol/L。葡萄糖在灌注开始时逐渐降低,灌注2 h时达最低值17.7 mmol/L,之后维持动态平衡。pH值在灌注6 h降低为7.28,乳酸水平在灌注1 h时升高,达到9.6 mmol/L,之后逐渐呈下降趋势。肌酸激酶水平从灌注开始升高,于2 h到达高峰,为20030 U/L,之后下降,在灌注结束时保持稳定。灌注结束肌纤维形态正常,肌纤维间隙略有增大,骨骼肌糖原未见明显蓄积。灌注0 h时血管内皮凋亡细胞数量较多,6 h时凋亡细胞数量减少。灌注0 h时血管充盈明显,6 h时指间部分血管充盈程度减低。结论人源化基因修饰猪血红细胞常温机械灌注人断肢能持续稳定的供能供氧,保持灌注液离子酸碱度平衡,维持细胞正常代谢,对离断肢体有一定保护作用。

Objective To evaluate the preservation effect of normothermic mechanical perfusion with red blood cells from humanized genetically modified pig on severed human limbs.Methods Severed human limbs were perfused with red blood cells from humanized genetically modified pigs for 6 h.Perfusion solution was taken every hour to measure the oxygen partial pressure,Na^(+),K^(+),Ca^(2+),pH value,glucose,lactic acid and creatine kinase levels.Superficial flexor muscle was sampled to detect the changes of tumor necrosis factor(TNF)-α,interleukin(IL)-2 and IL-1 levels.At 0 and 6 h after perfusion,the superficial flexor muscles of the forearm were taken for pathological examination.Intercellular space and glycogen consumption of skeletal muscles were observed.An appropriate amount of forearm vessels was collected every 2 h to detect the apoptosis of vascular endothelial cells.X-ray angiography was performed before perfusion and 6 h after perfusion to observe the filling degree of finger-tip peripheral vessels.Results The oxygen partial pressure was observed in the normal range throughout the perfusion.Na^(+)concentration peaked at 1 h,reaching 138.7 mmol/L,and then fluctuated within the normal range.K^(+)level peaked at 2 h up to 6.08 mmol/L,then decreased and fluctuated within the normal range.Ca^(2+)concentration reached the peak at 4 h,up to 1.03 mmol/L.Glucose level was gradually decreased at the beginning of perfusion,reaching the lowest value of 17.7 mmol/L at 2 h after perfusion,and then maintained a dynamic balance.The pH value was decreased to 7.28 at 6 h after perfusion.The lactic acid level was increased to 9.6 mmol/L at 1 h after perfusion,and then gradually decreased.The creatine kinase level was increased at the start of perfusion,reached the peak at 2 h up to 20030 U/L,then decreased and remained stable at the end of perfusion.At the end of perfusion,the morphology of muscle fibers was normal,the gap among muscle fibers was expanded slightly,and the glycogen of skeletal muscles was not significantly accumulated.At 0 h perfusion,the number of apoptotic cells in vascular endothelial cells was large,which was declined at 6 h perfusion.Evident vascular filling was observed at 0 h,and the filling degree of some finger-tip vessels was decreased at 6 h.Conclusions Normothermic mechanical perfusion of severed human limbs with red blood cells from humanized genetically modified pigs may continuously and stably supply energy and oxygen,adjust the ion pH balance of perfusion solution,maintain normal cellular metabolism and exerts certain protective effect upon severed human limbs.