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

前言：间歇性阻断(IC)和缺血预适应(I/PR)均可保护肝脏免受缺血/再灌注(I/R)损伤。虽然在肝切除术中使用了夹住15~20分钟再灌流5分钟的IC循环，但尚未确定最佳的IC循环，即夹闭和再灌流的最佳长度。目的：验证具有较短钳制/再灌流周期的IC的假设，并比较不同的IC和I/PR方案在减轻I/R损伤方面的效果。方法雄性Wistar大鼠2 5 0~2 70 g，随机分为5组：持续缺血60min组(60×1min，n=12)，缺血15min/5min组(15×4min，n=12)，缺血10min/3.3min组(10×6min，n=10)，缺血5min/1.7min组(5×12min，n=9)，预适应组(缺血10min，…10min缺血60min(I/Pr，n=9)。各组总缺血时间固定为60min，各IC组缺血时间与再灌注时间之比固定为3：1。再灌流3h后，通过检测血清ALT水平、胆汁流量、肝组织标本H&E染色、原位末端标记物(TUNEL)染色和DNA梯带染色以及组织谷胱甘肽(GSH)含量来评价肝损伤程度(仅IC组)。结果：实验数据以均值±扫描电子显微镜表示，分别为60×1min、15×12min、10*6min、5*12min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&lt；0.001)。胆汁流量(μg/ml)分别为230±70、620±60、760±80、980±70和190±50(p&lt；0.001)。H&E染色为：大片融合区组织破坏，轻度实质损伤，偶见细胞肿胀和胞浆空泡化，轻度改变，轻度改变，轻度实质损伤。TUNEL阳性肝细胞百分比(%)分别为：50、20~25、3、3、20~25。组织GSH含量(%)从基础值降至5 9.7±0.8、6 0.5±2.9、73.8±2.8和81.4±3.4(P&lt；0.001，未评估I/PR组)。结论：缺血再灌注周期短的IC对热I/R损伤的保护作用优于长周期的IC。在本研究中，I/Pr的保护作用并不一致。IC可能是一种比I/Pr更可靠的策略，无论钳制和再灌流周期的长度或评估的参数如何。较少

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