Gao W, Bentley R C, Madden J F, Clavien P A
Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA.
Hepatology. 1998 Jun;27(6):1652-60. doi: 10.1002/hep.510270626.
In livers excised for transplantation, sinusoidal endothelium appears especially vulnerable to injury during organ preservation in the cold and subsequent reperfusion. The degree of endothelial cell injury correlates with functional impairment of the graft following transplantation. The mechanism of injury remains obscure, but endothelial cell damage has been described as coagulative necrosis secondary to irreversible physico-chemical damage. We investigated whether endothelial cell death is caused by apoptosis rather than by necrosis. Tissue from rat livers stored for varying periods in cold (1 degree C) Euro-Collins solution and then reperfused for 1 hour at 37 degrees C were studied for evidence of apoptosis by detection of DNA fragmentation using the in situ terminal deoxynucleotidyl transferase d-uridine triphosphate nick end labeling (TUNEL) assay, DNA gel electrophoresis, and by transmission electron microscopy (EM). DNA fragmentation of the type characteristic of apoptosis was identified in 49.7% +/- 2.2% of sinusoidal lining cells after 8 hours of ischemia + reperfusion (viable graft) vs. 70.7% +/- 4.3% after 16 hours + reperfusion (nonviable graft) (P < .001). No such fragmentation was observed after cold preservation without reperfusion or in unpreserved, reperfused livers. EM demonstrated changes characteristic of apoptosis exclusively in endothelial cells. The study suggests that the apoptosis of sinusoidal endothelial cells is a pivotal mechanism of preservation injury in liver transplantation.
在用于移植而切除的肝脏中，肝血窦内皮细胞在低温器官保存及随后的再灌注过程中似乎特别容易受到损伤。内皮细胞损伤的程度与移植后移植物的功能损害相关。损伤机制尚不清楚，但内皮细胞损伤被描述为继发于不可逆物理化学损伤的凝固性坏死。我们研究了内皮细胞死亡是否由凋亡而非坏死引起。通过使用原位末端脱氧核苷酸转移酶d-UTP缺口末端标记（TUNEL）测定法检测DNA片段化、DNA凝胶电泳以及透射电子显微镜（EM），对在冷（1℃）欧洲柯林斯溶液中保存不同时间然后在37℃再灌注1小时的大鼠肝脏组织进行凋亡证据研究。在缺血+再灌注8小时（存活移植物）后，49.7%±2.2%的肝血窦内衬细胞中鉴定出凋亡特征性的DNA片段化，而在16小时+再灌注（非存活移植物）后为70.7%±4.3%（P<0.001）。在未再灌注的冷保存后或未保存但再灌注的肝脏中未观察到这种片段化。EM仅在内皮细胞中显示出凋亡特征性变化。该研究表明，肝血窦内皮细胞凋亡是肝移植中保存损伤的关键机制。
