Corps C L, Shires M, Crellin D, Smolenski R, Potts D, Pratt J, Lodge J P A
Transplant Science Group, Department of Hepatology and Transplantation, St. James's University Hospital, Leeds West Yorkshire LS9 7TF, United Kingdom.
Transplant Proc. 2009 Dec;41(10):4088-93. doi: 10.1016/j.transproceed.2009.07.107.
Cold flush preservation prolongs tissue viability during ischemia. However, there is little understanding of the effects of various preservation fluids on events during this period. A study of cold ischemia in rat livers was undertaken to compare biochemical and histological changes over time, using three preservation solutions: University of Wisconsin (UW), histidine-tryptophan-ketoglutarate (HTK), and Leeds solution (LS) under development at our institution. Leeds solution is a phosphate-based sucrose solution that like UW contains the impermeant lactobionate and the metabolite allopurinol (1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one) which acts as a competitive inhibitor of xanthine oxidase, stopping the breakdown of hypoxanthine to xanthine by oxidizing it to alloxanthine, inhibiting both the conversion of hypoxanthine to xanthine and the conversion of xanthine to uric acid.
At various time points, samples were analyzed for adenosine triphospate (ATP) and metabolites by high-performance liquid chromatography as well as for histological changes.
In all livers, ATP, ADP, and AMP degraded over 4 hours. In UW and LS groups, degradation beyond hypoxanthine was halted, and it continued in the HTK group. This blockade led to a significant reduction in the accumulation of xanthine and uric acid. Histological analysis showed protected architecture and maintenance of reticulin scaffolds in the UW and LS groups, whereas tissue breakdown was seen from earlier time points in the HTK group. Additionally, throughout ischemia, signs of pathological injury were more pronounced with UW- than with LS-preserved tissue.
These results implied that cold ischemia in the liver is characterized by dynamic biochemical changes coincident with pathological injury which are initiated from the time of organ perfusion and influenced by the choice of the perfusion fluid. Allopurinol in UW and LS appears to be critical. We hypothesized that it may also affect the degree of subsequent reperfusion injury. The data supported the assertion that LS offerred improved preservation over UW, adding to the impetus to shorten ischemic times in clinical transplantation.
冷灌注保存可延长缺血期间组织的存活时间。然而，对于各种保存液在此期间对相关事件的影响了解甚少。本研究对大鼠肝脏冷缺血进行了研究，使用三种保存液：威斯康星大学（UW）溶液、组氨酸 - 色氨酸 - 酮戊二酸（HTK）溶液以及本校正在研发的利兹溶液（LS），比较随时间变化的生化和组织学改变。利兹溶液是一种基于磷酸盐的蔗糖溶液，与UW溶液一样含有非渗透性的乳糖酸盐和代谢物别嘌呤醇（1,5 - 二氢 - 4H - 吡唑并[3,4 - d]嘧啶 - 4 - 酮），别嘌呤醇作为黄嘌呤氧化酶的竞争性抑制剂，通过将次黄嘌呤氧化为别黄嘌呤来阻止次黄嘌呤分解为黄嘌呤，从而抑制次黄嘌呤向黄嘌呤的转化以及黄嘌呤向尿酸的转化。
在不同时间点，通过高效液相色谱分析样本中的三磷酸腺苷（ATP）和代谢物，并观察组织学变化。
在所有肝脏中，ATP、ADP和AMP在4小时内降解。在UW组和LS组中，次黄嘌呤之后的降解停止，而在HTK组中继续。这种阻断导致黄嘌呤和尿酸的积累显著减少。组织学分析显示，UW组和LS组的结构得到保护，网状纤维支架得以维持，而在HTK组中，从较早时间点就可见组织破坏。此外，在整个缺血过程中，UW保存的组织比LS保存的组织病理损伤迹象更明显。
这些结果表明，肝脏冷缺血的特征是与病理损伤同时发生的动态生化变化，这些变化从器官灌注时开始，并受灌注液选择的影响。UW溶液和LS溶液中的别嘌呤醇似乎至关重要。我们推测它可能也会影响随后再灌注损伤的程度。数据支持了LS溶液比UW溶液提供更好保存效果的论断，这进一步推动了在临床移植中缩短缺血时间的进程。
