Pathophysiology of the liver and development of a novel therapeutics based on morphological and functional study on hepatic sinusoidal

1.低温保存对肝脏损伤保护作用的研究。在我们以前的研究中，我们阐明了库普弗细胞激活过程中冷保存，诱导损伤的模拟内皮细胞（SEc）通过组织毒性介质。在本研究中，我们试图证明SEC损伤的另一种机制，即凋亡，因为SEC损伤出现在比Kupffer细胞活化更早的时期。通过电镜和Tunel法研究了SEC在低温保存过程中的高频率凋亡变化。此外，我们发现血管内皮生长因子（VEGF）参与了细胞凋亡的抑制。此外，我们研究了冷冻保存的脂肪肝的超微结构改变，这是基于脂肪肝是原发性无功能移植物的主要危险因素之一的证据。我们发现SEC损伤在冷藏前就已发生，然后在冷藏过程中发生。形态学的变化， ...更多信息 SEC中气泡形成增多，间隙扩大，呈线状。肝细胞中，随着冷保存时间的延长，脂肪滴体积增大，并占据胞浆。这种改变导致了上颌窦的压迫和窦径的狭窄。提示肝窦微循环障碍可能是脂肪肝移植失败的原因之一。2. Ito细胞中钠钙交换体的发现Ito细胞粘附于窦外膜，通过自身收缩参与窦循环的调节。这种收缩受细胞质Ca离子浓度的调节。本研究首次在Ito细胞中发现了钠钙交换蛋白，并进一步发现其mRNA和蛋白的表达与Ito细胞活化和肝纤维化密切相关。3.一氧化氮在肝硬化门脉血流动力学中的意义。近年来，越来越多的证据表明，NO与肝硬化的高动力性改变密切相关。然而，NO在此病理中的作用仍有待解决。本研究证实NO在CCl_4诱导的肝硬化门脉高压血流动力学中起重要作用，NO是评价门脉高压的一个有用指标。此外，发现血清NO水平的增加至少部分来自肝、脾和肺中iNOSmRNA表达的增加。少

1.Study on protection of hepatic damage during cold preservation. In our previous studies, we clarified Kupffer cell activation during cold preservation, inducing an injury of simusoidal endothelial cells(SEc) through tissue toxic mediators. In the present study, we attempted to prove an alternative mechanism of SEC injury, that is apoptosis, because SEC damage appeared at earlier peroid than Kupffer cell activation. Consequently, we made clear the apoptotic change of SEC with high frequency during cold preservation by electron microscopy and Tunel method. Furthermore, we found that vascular endothelial growth factor(VEGF) contributed to the suppresssion of apoptosis. In addition, we studied an ultrastructural alteration of cold-preserved fatty liver based on the evidence that a datty liver is one of main risk factors for primary nonfunctioning graft. We found that SEC damage proceeded prior to cold preservation and then accerelated during the preservation. The morphological changes we … More re increase in bleb formation, expansion of gap and string-like appearance in SEC.With regard to hepatocytes, size of fat droplets was enlarged with the duration of cold preservation, and then occupied cytoplasma. This change caused the oppression of sunusoid and narrowness of sinusoidal caliber. These findings suggested that a causative mechanism of graft failure in the transplantation of fatty liver may be microcirculatory disturbance of hepatic sinusoid. 2.Discovery of Na-Ca exchanger in Ito cells. Ito cells are adhered to outlayr of sinusoid, and is considered to be participated in the regulation of sinusoidal circulation by the own contraction. This contraction is regulated by the cytoplasmic Ca ion concentration. In the present study, we discovered first Na-Ca exchanger in Ito cells and further found that the expression of the mRNA and the protein was closely correlated with the activation of Ito cells and liver fibrosis. 3.Significance of nitric oxide(NO) in portal hemodynamics of liver cirrhosis. More recently, evidence has accumulated indicating that NO is closely related to the hyperdynamic change seen in the liver cirrhosis. However, the role of NO in this pathology is still remained to be resolved. In the present study we demonstrated that NO plays a significant role in portal hypertensive hemodynamics in CCl_4-induced liver cirrhosis, and that NO is a useful indicator for the evaluation of portal hypertension. Furthermore, the increased serum levels of NO were found to be derived at least in part from the increased expression of iNOSmRNA in the liver, spleen and lung. Less