[Orexin-A in hepatic reperfusion-induced liver injury in rats].

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 sham-operation 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 immunohistochemistry 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 positive linear correlation between the plasma orexin-A and serum glucose and total anti-oxidation 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 participates in the modulation of hepatic reperfusion-induced liver injury and internal disorders.