Fukumori T, Ohkohchi N, Tsukamoto S, Satomi S
Second Department of Surgery, Tohoku University School of Medicine, Sendai, Japan.
Transplantation. 1999 Jan 27;67(2):195-200. doi: 10.1097/00007890-199901270-00002.
Fatty livers are more prone to primary nonfunction after transplantation. It is known that cell injury is strongly associated with alterations in the content and composition of membrane lipids. We assumed that plasma membrane (PM) fluidity, which is the most important property of the membrane, differed between fatty and normal livers.
The livers from obese and lean Zucker rats were flushed with cold Ringer's lactate and University of Wisconsin (UW) solution via the portal vein and preserved in cold UW solution for 24 hr. Histological examinations of electron microscopy were performed to investigate of sinusoidal lining cells (SLCs). PMs were isolated using a discontinuous density gradient of Percoll, and the lipid compositions were determined by chromatography.
SLCs of fatty livers were markedly injured compared with control livers even after short preservation time. Moreover, many blebs were observed in the obese rats even after short preservation time. As for PM lipid composition, the cholesterol/phospholipid (PL) ratio of total PM was 0.14+/-0.03 in the obese rats and 0.21+/-0.03 in the lean rats (P<0.05). The relative proportions of polyunsaturated fatty acids among PLs in PM were 35.7+/-1.2% vs. 45.9+/-1.5% (P<0.0001). These results indicated that the fluidity of the PM in the obese rats is decreased after exposure to low temperatures.
Our results suggest that steatotic livers from obese donors are more susceptible to cold preservation injury than livers without steatosis because of the severe deterioration of SLCs, and it is associated with PM fluidity even after short-term cold preservation.
脂肪肝在移植后更易发生原发性无功能。已知细胞损伤与膜脂质的含量和组成改变密切相关。我们推测，作为膜最重要特性的质膜（PM）流动性在脂肪肝和正常肝脏之间存在差异。
通过门静脉用冷乳酸林格氏液和威斯康星大学（UW）溶液冲洗肥胖和瘦型 Zucker 大鼠的肝脏，并在冷 UW 溶液中保存 24 小时。进行电子显微镜组织学检查以研究窦状隙衬里细胞（SLCs）。使用不连续的 Percoll 密度梯度分离质膜，并通过色谱法测定脂质组成。
即使在短时间保存后，脂肪肝的 SLCs 与对照肝脏相比也明显受损。此外，即使在短时间保存后，肥胖大鼠中也观察到许多泡状突起。至于质膜脂质组成，肥胖大鼠总质膜的胆固醇/磷脂（PL）比率为 0.14±0.03，瘦型大鼠为 0.21±0.03（P<0.05）。质膜中磷脂中多不饱和脂肪酸的相对比例分别为 35.7±1.2%和 45.9±1.5%（P<0.0001）。这些结果表明，肥胖大鼠的质膜在暴露于低温后流动性降低。
我们的结果表明，来自肥胖供体的脂肪变性肝脏比无脂肪变性的肝脏更容易受到冷保存损伤，这是因为 SLCs 严重恶化，并且即使在短期冷保存后也与质膜流动性有关。
