Hart Melanie L, Much Chressen, Köhler David, Schittenhelm Jens, Gorzolla Iris C, Stahl Gregory L, Eltzschig Holger K
Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Am J Physiol Gastrointest Liver Physiol. 2008 Jun;294(6):G1431-40. doi: 10.1152/ajpgi.00083.2008. Epub 2008 Apr 24.
Ischemic preconditioning (IP) represents a powerful experimental strategy to identify novel molecular targets to attenuate hepatic injury during ischemia. As a result, murine studies of hepatic IP have become an important field of research. However, murine IP is technically challenging, and experimental details can alter the results. Therefore, we systematically tested a novel model of hepatic IP by using a hanging-weight system for portal triad occlusion. This system has the benefit of applying intermittent hepatic ischemia and reperfusion without manipulation of a surgical clamp or suture, thus minimizing surgical trauma. Systematic evaluation of this model revealed a close correlation of hepatic ischemia time with liver damage as measured by alanine (ALT) and aspartate (AST) aminotransferase serum levels. Using different numbers of IP cycles and times intervals, we found optimal liver protection with four cycles of 3 min ischemia/3 min reperfusion as measured by ALT, AST, lactate dehydrogenase, and interleukin-6. Similarly, ischemia-associated increases in hepatic infarct size, neutrophil infiltration, and histological injury were maximally attenuated with the above regimen. To demonstrate transcriptional consequences of liver IP, we isolated RNA from preconditioned liver and confirmed transcriptional modulation of known target genes (equilibrative nucleoside transporters, acute-phase complement genes). Taken together, these studies confirm highly reproducible liver injury and protection by IP when using the hanging-weight system for hepatic ischemia and intermittent reperfusion. Further studies of murine IP may consider this technique.
缺血预处理（IP）是一种强大的实验策略，用于识别减轻缺血期间肝损伤的新分子靶点。因此，对肝缺血预处理的小鼠研究已成为一个重要的研究领域。然而，小鼠缺血预处理在技术上具有挑战性，实验细节可能会改变结果。因此，我们通过使用悬挂重物系统阻塞肝门三联，系统地测试了一种新的肝缺血预处理模型。该系统的优点是可以进行间歇性肝缺血和再灌注，而无需操作手术夹或缝线，从而将手术创伤降至最低。对该模型的系统评估显示，肝缺血时间与通过丙氨酸（ALT）和天冬氨酸（AST）转氨酶血清水平测量的肝损伤密切相关。使用不同数量的缺血预处理周期和时间间隔，我们发现，以ALT、AST、乳酸脱氢酶和白细胞介素-6衡量，3分钟缺血/3分钟再灌注的四个周期可实现最佳的肝脏保护。同样，上述方案可最大程度地减轻缺血相关的肝梗死面积增加、中性粒细胞浸润和组织学损伤。为了证明肝缺血预处理的转录后果，我们从预处理的肝脏中分离RNA，并证实了已知靶基因（平衡核苷转运体、急性期补体基因）的转录调节。综上所述，这些研究证实，当使用悬挂重物系统进行肝缺血和间歇性再灌注时，缺血预处理对肝脏损伤和保护具有高度可重复性。对小鼠缺血预处理的进一步研究可能会考虑采用这种技术。
