食欲素-A在大鼠肝再灌注诱导的肝损伤中的变化

Orexin-A in hepatic reperfusion-induced liver injury in rats

目的:研究食欲素-A(orexin-A)在肝再灌注时的表达变化及其与肝损伤的联系,探讨orexin-A在创伤应激反应中的作用。方法:建立大鼠70%肝再灌注模型,设立假手术和不同再灌注时间的损伤组,采用自制放射免疫分析法和试剂盒检测损伤后血浆、下丘脑orexin-A的蛋白水平和血清葡萄糖、总抗氧化能力、丙氨酸氨基转移酶,HE染色、免疫组织化学检测肝的病理学改变、orexin-A蛋白表达,RT-PCR观察下丘脑、肝orexin-AmRNA表达。结果:自制orexin-A放射免疫分析法的标准曲线形态和测量结果均良好。各再灌注组血浆、下丘脑orexin-A的蛋白水平无显著变化,损伤后期血清葡萄糖、总抗氧化能力显著升高,血浆orexin-A与血清葡萄糖、总抗氧化能力均存在显著的线性正相关;各再灌注组血清丙氨酸氨基转移酶显著升高,损伤后期肝损害显著减轻。各再灌注组肝orexin-A蛋白表达和下丘脑、肝orexin-AmRNA表达有不同程度的变化。结论:Orexin-A在肝再灌注时发生显著的表达变化,提示它参与调控肝再灌注诱导的肝损伤和内环境紊乱。

Objective To explore the change of orexin-A expression in hepatic reperfusion and their association with liver injury, and to find out the role of orexin-A in traumatic stress responses. Methods A 70 % hepatic reperfusion model of rats was established, setting groups of shamoperation and injury ones with different reperfusion time. A self-produced radioimmunoassay and relevant kits were used to detect the protein level of orexin-A in the plasma and the hypothalamus, serum glucose, total anti-oxidation capacity and alanine transaminase, HE staining and immunohistoehemistry were used to investigate the pathological variation and protein expression of orexin-A in the liver, while RT-PCR was applied to observe mRNA expression of orexin-A in the hypothalamus and the liver. Results Both the shape of standard curve and metrical results of the self-produced orexin-A radioimmunoassay were good. Protein levels of orexin-A in the plasma and the hypothalamus in each reperfusion group showed no significant change. Serum glucose and total anti-oxidation capacity increased significantly at the later phase of injury. There was significant and between the plasma orexin-A and serum glucose and total anti-oxidation positive linear correlation capacity ; serum alanine transaminase in each reperfusion group was significantly higher, and liver damage was significantly alleviated at the later phase of the injury. Different extents of variation were observed in protein expression of orexin-A in the liver and its mRNA expression in the hypothalamus and the liver. Conclusion Orexin-A undergoes significant changes during hepatic reperfusion, indicating that orexin-A partici- pates in the modulation of hepatic reperfusion-induced liver injury and internal disorders.