肝缺血/再灌注损伤对血浆及下丘脑orexin-A表达的影响

Effect of hepatic ischemia/reperfusion injury on orexin-A expression levels in plasma and hypothalamus

目的探讨肝缺血/再灌注(H-I/R)损伤对血浆和下丘脑orexin-A表达的影响。方法采用微型无损伤血管夹夹闭肝蒂左分叉的方法制备大鼠70%H-I/R模型,设立假手术组(sham)和缺血1 h后再灌注1 h、2.5 h、4 h、6 h损伤组。采用放射免疫法检测H-I/R损伤后血浆和下丘脑orexin-A的水平,并采用reverse transcription-PCR(RT-PCR)方法检测下丘脑orexin-A mRNA的表达。结果各再灌注组血浆和下丘脑orexin-A的水平与损伤后sham组比较,差异均无统计学意义(P>0.05)。而血浆orexin-A水平在I/R1 h组显著高于I/R6 h组(P<0.05)。I/R4 h和I/R6 h组下丘脑orexin-A mRNA的表达水平显著高于sham和I/R1 h组(P<0.05)。结论 H-I/R可引起orexin-A表达水平一定程度的变化,orexin-A参与创伤应激后代谢紊乱的调控。

Objective To explore the effect of hepatic ischemia/reperfusion （H-I/R） injury on orexin-A expression levels in plasma and hypothalamus. Methods The blood vessels supplying hepatic pedicle left branch were occluded by micro-vascular clamp to establish 70% H-I/R rat models. Forty rats were divided into sham group and 1 h ischemia/1 h reperfusion（I/R1 h）,I/R2.5 h,I/R4 h and I/R6 h groups.Radioimmunoassay was used to measure orexin-A levels in plasma and hypothalamus,and RT-PCR was used to measure orexin mRNA expression in hypothalamus of rats.Results Compared with sham group,orexin-A levels in plasma and hypothalamus showed no significant difference in reperfusion groups.The plasma orexin-A level in L/R1 h group was significantly higher than that in I/R6 h group（P 〈 0.05）.The orexin-A mRNA expression levels in hypothalamus in I/R4 h and I/R6 h group were significantly higher than those in sham group and I/R1 h group（P 〈 0.05）.Conclusion H-I/R might induce a certain degree of changes of orexin-A expression levels,and orexin-A might participate in the modulation of metabolic disorders after traumatic stress.