Extension of limitation on hepatic warm ischemia, with special reference to analysis of the microcirculatory disturbance and the mechanism of ischemic tolerance from the view points of stress responce protein

肝脏热缺血限制的延伸，特别是从应激反应蛋白的角度分析微循环障碍和缺血耐受机制

基本信息

批准号：
09671300
负责人：
NOGUCHI Takashi
金额：
$ 1.15万
依托单位：
Mie University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

<Purpose> This study was performed to investigate the cytoprotective effect of ischemic tolerance established by initial transient ischemia as a sub lethal stress or administration of Geranyl-geranyl-acetone (GGA),which are known to be one of heat shock protein (Hsp) inducers, make an extension of hepatic warm ischemia limit, and to evaluate the mechanism ischemic tolerance, hepatic microcirculation and endothelial cell function with in vivo to in vitro. Moreover, small intestinal model was evaluated as well as hepatic model.<Materials & Methods> Male wistar rats were subjected to 45 min of hepatic ischemia followed reperfusion : (1) 20 min liver ischemia 7 days prior to 45 min ischemia, or (2) oral administration of GGA 200 mg/kgBW for 7 or 14 days prior to 45 min ischemia. Examined were survival rate, liver function, hepatic tissue blood flow, histologic findings, expression of Hsp 70 and NF-kB (Western blot), and NOィイD22ィエD2 + NOィイD23ィエD2 concentration in isolated hepatocyte/non-par … More enchymal cell cultures 8Griess method). In intestinal models which were subjected to 90 min superior mesenteric artery clumped, preconditioning groups were (1) 30 min initial ischemia 7 days prior to 90 min ischemia and (2) oral administration of GGA 14 days prior to 90 min ischemia.<Results> 1. The 7-day survival rate : all animals of 45 min ischemia were died within 48 hrs after reperfusion, in contrast, preconditioning groups were significantly higher (83% and 75%) respectively. 2. In preconditioning groups, ALT & HA levels in the serum, hepatic blood flow, and histologic findings including increased apoptosis in hepatocytes and endothelial cells showed a significant improvement . 3. Hsp 70 induction was remarkably increased immediately after reperfusion to 6 hrs. 4. The expression and activation of NF-kB were significantly suppressed. 5. The NO production was inhibited by iNOS in preconditioning groups. 6. Intestinal ischemia limit was extended by preconditioning and apoptosis was regulated with increased Hsp 70 expression.<Conclusion> Ishemic preconditioning and oral administration of GGA protected liver sinusoidal endothelial cell dysfunction and improved the hepatic microcirculatory disturbance in the postischemic liver by inducing Hsp 70. This Hsp 70 suppresses NF-kB to regulate the overproduction of NO attribute to iNOS. Preconditioning by ischemia or drugs establishes ischemic tolerance in small intestine as well as liver. Therefore, performing the ischemic preconditioning is expected to be of much benefit to extend hepatectomy, or liver transplantation and so on. Less

<目的> 本研究旨在研究通过初始短暂性缺血作为亚致死应激或给予已知为热休克蛋白 (Hsp) 之一的香叶基-香叶基-丙酮 (GGA) 建立的缺血耐受的细胞保护作用诱导剂，延长肝脏热缺血极限，并从体内到体外评价其缺血耐受机制、肝脏微循环和内皮细胞功能。此外，还建立了小肠模型。 <材料与方法> 雄性 Wistar 大鼠再灌注后进行 45 分钟肝缺血：(1) 45 分钟缺血前 7 天进行 20 分钟肝缺血，或 (2) 口服 GGA 200缺血 45 分钟前 7 或 14 天，检查存活率、肝功能、肝组织血液。血流、组织学结果、Hsp 70 和 NF-kB 的表达（Western blot），以及分离的肝细胞/非 par 中的 NOID22D2+NOID23D2 浓度……更多骨髓细胞培养物 8Griess 方法）在接受 90 分钟肠系膜上动脉的肠道模型中成团的预处理组为 (1) 7 天前 30 分钟初始缺血90分钟缺血和（2）在90分钟缺血前14天口服GGA。 <结果> 1. 7天存活率：所有45分钟缺血的动物在再灌注后48小时内死亡，相比之下，预处理组2.在预处理组中，血清、肝血流中的 ALT 和 HA 水平分别显着较高（83% 和 75%）。包括肝细胞和内皮细胞凋亡增加在内的组织学结果显示出显着改善。 3. 再灌注后 6 小时，Hsp 70 诱导显着增加。 4. NF-kB 的表达和激活显着受到抑制。 6. 预处理组中 iNOS 抑制了肠缺血极限，并且 Hsp 70 的增加调节了细胞凋亡。 <结论> 缺血预处理和口服GGA可通过诱导Hsp 70保护肝窦内皮功能障碍细胞并改善缺血后肝脏的肝微循环障碍。该Hsp 70抑制NF-kB以调节iNOS引起的NO过量产生。通过缺血或药物进行预处理可建立小肠和肝脏的缺血耐受性，因此进行缺血预处理是重要的。预计延长肝切除术或肝移植等获益较少。