内源性血红素加氧酶的诱导是肢体缺血/再灌注后减轻细胞凋亡和恢复微血管灌注的关键机制。

Endogenous heme oxygenase induction is a critical mechanism attenuating apoptosis and restoring microvascular perfusion following limb ischemia/reperfusion.

作者信息

McCarter Sarah D, Akyea Thelma G, Lu Xiangru, Bihari Aurelia, Scott Jeffrey R, Badhwar Amit, Dungey Alison A, Harris Kenneth A, Feng Qingping, Potter Richard F

机构信息

Department of Medical Biophysics, University of Western Ontario, and the London Health Science Centre and Lawson Health Research Institute, London, Ontario, Canada.

出版信息

Surgery. 2004 Jul;136(1):67-75. doi: 10.1016/j.surg.2003.11.002.

DOI:10.1016/j.surg.2003.11.002

PMID:15232541

Abstract

BACKGROUND

A protective role for endogenous heme oxygenase (HO) in the initiation of remote liver injury after limb ischemia/reperfusion has been established. This study expands on our previous work by investigating the role of endogenous HO on hepatocellular injury, hepatocyte death (necrotic and apoptotic), and microvascular perfusion at protracted post-reperfusion times.

METHODS

Remote liver injury was studied after 1 hour of bilateral hind limb ischemia and 3, 6, or 24 hours of reperfusion in male C57BL6 mice. Inhibition of HO was achieved with the use of chromium mesoporphrin (CrMP). Established intravital videomicroscopy techniques were used to evaluate microvascular perfusion and hepatocyte death. Hepatocellular injury was quantified by serum alanine transaminase. Apoptosis was measured by using DNA laddering, Cell Death ELISA, and caspase-3 activity.

RESULTS

Although significant perfusion deficits and hepatocellular injury/death occurred after 3 hours, progression of hepatocellular death beyond 6 hours was not observed. A transient increase in apoptosis was observed at 6 hours. By 24 hours, microvascular perfusion was completely restored. This lack of progression correlated with increased HO activity, observed throughout the protocol. Administration of CrMP reduced HO activity to sham nonstressed levels, and caused increased microvascular perfusion deficits, hepatocellular injury, and hepatocyte death over 24 hours. The transient increase in apoptosis was increased in duration and magnitude in CrMP-treated animals.

CONCLUSIONS

These results suggest that endogenous HO activity prevents the progression of remote liver injury after limb ischemia/reperfusion.

摘要

背景

内源性血红素加氧酶（HO）在肢体缺血/再灌注后引发的远隔肝损伤中具有保护作用，这一点已得到证实。本研究通过调查内源性HO在再灌注后较长时间对肝细胞损伤、肝细胞死亡（坏死和凋亡）以及微血管灌注的作用，对我们之前的工作进行了拓展。

方法

在雄性C57BL6小鼠双侧后肢缺血1小时及再灌注3、6或24小时后研究远隔肝损伤。使用中卟啉铬（CrMP）抑制HO。采用已确立的活体视频显微镜技术评估微血管灌注和肝细胞死亡。通过血清丙氨酸转氨酶对肝细胞损伤进行定量分析。使用DNA梯状条带分析、细胞死亡酶联免疫吸附测定法和半胱天冬酶-3活性检测细胞凋亡。

结果

虽然在3小时后出现了显著的灌注不足和肝细胞损伤/死亡，但未观察到6小时后肝细胞死亡的进展。在6小时时观察到凋亡短暂增加。到24小时时，微血管灌注完全恢复。这种缺乏进展的情况与整个实验过程中观察到的HO活性增加相关。给予CrMP可将HO活性降低至假手术非应激水平，并在24小时内导致微血管灌注不足、肝细胞损伤和肝细胞死亡增加。在CrMP处理的动物中，凋亡的短暂增加在持续时间和幅度上均增加。