Wan Lili, Powell-Palm Matthew J, Lee Charles, Gupta Anshal, Weegman Bradley P, Clemens Mark G, Rubinsky Boris
Department of Cardiovascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, People's Republic of China; Department of Mechanical Engineering and Department of Bioengineering, University of California, Berkeley, Berkeley, CA, 94720, USA.
Department of Mechanical Engineering and Department of Bioengineering, University of California, Berkeley, Berkeley, CA, 94720, USA.
Biochem Biophys Res Commun. 2018 Feb 12;496(3):852-857. doi: 10.1016/j.bbrc.2018.01.140. Epub 2018 Feb 1.
Isochoric (constant volume) preservation at subfreezing temperatures is being investigated as a novel method for preserving cells and organs. This study is a first initial effort to evaluate the efficacy of this method for heart preservation, and to provide a preliminary outline of appropriate preservation parameters. To establish a baseline for further studies, rat hearts were preserved in a University of Wisconsin (UW) intracellular solution for one hour under isochoric conditions at: 0 °C (atmospheric pressure - 0.1 MPa), - 4 °C (41 MPa), - 6 °C (60 MPa) and - 8 °C (78 MPa). The viability of the heart was evaluated using Langendorff perfusion and histological examination. The physiological performance of hearts preserved at - 4 °C (41 MPa) was comparable to that of a heart preserved on ice at atmospheric pressure, with no statistically significant difference in histological injury score. However, hearts preserved at -4 °C displayed substantially reduced interstitial edema compared to hearts preserved by conventional hypothermic preservation in UW on ice at atmospheric pressure, suggesting significant protection from increased vascular permeability following preservation. Hearts preserved at - 6 °C (60 MPa) suffered injury from cellular swelling and extensive edema, and at - 8 °C (78 MPa) hearts experienced significant morphological disruption. To the best of our knowledge, this is the first publication showing that a mammalian organ can survive low subfreezing temperatures without the use of a cryoprotective additive. Lowering the preservation temperature reduces metabolism and improves preservation quality, and these results suggest that improvements in preservation are possible at subzero temperatures with low to moderate pressures observed at -4 °C. Notably, tissue damage was observed at lower temperatures (-6 °C or below) accompanying further elevation of pressure associated with isochoric preservation that may prove detrimental. Therefore, subfreezing temperature isochoric preservation protocols should optimize, a combination of temperature and pressure that will minimize the negative effects of elevated pressure while retaining the beneficial effect of lower temperatures and reduced metabolism.
在亚冰点温度下进行等容（恒容）保存作为一种保存细胞和器官的新方法正在被研究。本研究是评估该方法用于心脏保存的有效性并提供合适保存参数初步概述的首次尝试。为了为进一步研究建立基线，将大鼠心脏在威斯康星大学（UW）细胞内溶液中于等容条件下在以下温度保存1小时：0°C（大气压 - 0.1MPa）、-4°C（41MPa）、-6°C（60MPa）和 -8°C（78MPa）。使用Langendorff灌注和组织学检查评估心脏的活力。在 -4°C（41MPa）保存的心脏的生理性能与在大气压下冰上保存的心脏相当，组织学损伤评分无统计学显著差异。然而，与在大气压下冰上用UW常规低温保存的心脏相比，在 -4°C保存的心脏间质水肿明显减轻，这表明在保存后对血管通透性增加有显著保护作用。在 -6°C（60MPa）保存的心脏因细胞肿胀和广泛水肿而受损，在 -8°C（78MPa）心脏出现明显的形态破坏。据我们所知，这是首次发表的表明哺乳动物器官在不使用冷冻保护添加剂的情况下能够在低亚冰点温度下存活的文章。降低保存温度可降低代谢并提高保存质量，这些结果表明在 -4°C观察到的低至中等压力下，在零下温度下改善保存是可能的。值得注意的是，在较低温度（-6°C或更低）下观察到组织损伤，同时等容保存相关压力进一步升高，这可能是有害的。因此，亚冰点温度等容保存方案应优化温度和压力的组合，以在保留较低温度和降低代谢的有益效果的同时，将压力升高的负面影响降至最低。
