The effect of various methods of inflow occlusion techniques in a rat liver resection on the extent of the liver injury and liver regeneration

简介：间歇性钳夹（IC）和缺血预处理（I/Pr）均能保护肝脏免受缺血/再灌注（I/R）损伤。虽然在肝切除期间经验性地使用由15至20分钟的夹持与5分钟的再灌注交替组成的IC周期，但是最佳IC周期，即，还没有确定最佳的夹紧和再灌注长度。目的：为了检验这一假设，即IC与较短的钳夹/再灌注周期是可取的，并比较各种IC和I/Pr协议在减少I/R损伤的疗效。方法雄性Wistar大鼠体重250- 270 g的雄性Wistar大鼠随机分为5组;持续缺血60分钟（60*1 min，n=12），15 min缺血/5 min再灌注4个周期（15*4 min，n=12），6个循环，10 min缺血/3.3min再灌注缺血10 min/再灌注1.7 min（5 × 12 min，n=9）;预处理（缺血10 min/再灌注10 min，n=10）; ...更多信息 缺血60分钟前（I/Pr，n=9）。所有组的总缺血时间固定为60分钟，并且每个IC组的缺血时间与再灌注时间的比率固定为3：1。再灌注3 h后，通过测定血清ALT水平、胆汁流量、肝组织H&E染色、TUNEL染色和DNA梯状条带作为细胞凋亡的特异性标志物以及组织谷胱甘肽（GSH）含量（仅IC组）来评估肝损伤的严重程度。结果如下：数据以平均值± SEM表示，分别按实验组的以下顺序：60*1分钟、15*12分钟、10*6分钟、5*12分钟和I/Pr组。血清ALT水平（IU/L）分别为4227±482、3202±400、2044±191、761±108和6981±691（p<0.001）。胆汁流量（μg/ml）分别为230±70、620±60、760±80、980±70和190±50（p<0.001）。H&E染色：组织破坏的大融合区域、轻度实质损伤（包括偶尔的细胞肿胀和细胞质空泡化）、极轻微改变、极轻微改变和轻度实质损伤。TUNEL阳性肝细胞的百分比（%）为：>50、20-25、<3、<3和20-25。组织GSH含量（%）从基线值降至59.7±0.8、60.5±2.9、73.8±2.8和81.4±3.4（p<0.001，未评估I/Pr组）。结论：在对热I/R损伤的保护方面，缺血和再灌注周期短的IC似乎比周期长的IC更有效。在本研究中，I/Pr的保护作用并不均匀。IC可能是比I/Pr更稳健的策略，无论钳夹和再灌注周期的长度或评估的参数如何。少

Introduction : Both intermittent clamping (IC) and ischemic preconditioning (I/Pr) have been shown to protect the liver against ischemia/reperfusion (I/R) injury. While IC cycles consisting of 15 to 20 minutes' clamping alternating with 5 minutes' reperfusion are used empirically during liver resection, the optimal IC cycle, i.e., the optimal lengths of clamping and reperfusion, are not yet established. Aim : To examine the hypothesis that IC with shorter clamping/reperfusion cycles are desirable, and to compare various IC and I/Pr protocols in terms of their efficacy in reducing I/R injury. Methods Male Wistar rats (250-270g) were randomly assigned into five groups ; 60 minutes' continuous ischemia (60*1 min, n=12), 4 cycles of 15 minutes' ischemia/5 minutes' reperfusion (15*4 min, n=12), 6 cycles of 10 minutes' ischemia/3.3 minutes' reperfusion (10*6 min, n=10), 12 cycles of 5 minutes' ischemia/1.7 minutes' reperfusion (5*12 min, n=9), preconditioning (10 minutes' ischemia and 10 min … More utes' reperfusion) prior to 60 minutes' ischemia (I/Pr, n=9). The total ischemic time was fixed at 60 minutes in all the groups, and the ratio of the ischemic time to reperfusion time was fixed at 3:1 in each of the IC groups. After 3 hours of reperfusion, the severity of liver injury was assessed by measuring the serum ALT levels, bile flow, H&E staining of liver specimens, TUNEL staining and DNA laddering as specific markers of apoptosis, and the tissue gluthatione (GSH) content (IC groups only). Results : The data were presented as mean± SEM in the following order of experimental groups, respectively : 60*1 min, 15*12 min, 10*6 min, 5*12 min, and I/Pr groups. The serum ALT levels (IU/L) were 4227±482, 3202±400, 2044±191, 761±108, and 6981±691 (p<0.001). Bile flow (μg/ml) were 230±70, 620±60, 760±80, 980±70, and 190±50 (p<0.001). H&E staining were : large confluent areas of tissue destruction, mild parenchymal injury including occasional cellular swelling and cytoplasmic vacuolization, minimal alterations, minimal alterations, and mild parenchymal injury. The percentages of TUNEL-positive hepatocytes (%) were : >50, 20-25, <3 , <3 , and 20-25. The tissue GSH content (%) decreased from baseline value to 59.7±0.8, 60.5±2.9, 73.8±2.8, and 81.4±3.4 (p<0.001, I/Pr group was not assessed). Conclusion : In terms of protection against warm I/R injury, IC with shorter cycles of ischemia and reperfusion appears to be more effective than that with longer cycles. The protective effect of I/Pr was not uniform in the present study. IC may be a more robust strategy than I/Pr, regardless of the lengths of the cycles of clamping and reperfusion or the parameters evaluated. Less