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

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 I /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.