RESUMO
ObjectiveTo investigate the effect of infusion of esmolol on expression of hypoxia inducible factor-1α following spinal ischemia-reperfusion (I/R) in rats.MethodsThirty-six healthy male Wistar rats weighing 300-350 g were randomly assigned into 3 groups (n =12 each):group Ⅰ sham operation (group S); group Ⅱ spinal I/R and group Ⅲ esmolol pretreatment (group E).Spinal ischemia was produced by cross-clamping of abdominal aorta distal to renal artery for 20 min in I/R and E groups,Infusion of esmolol 200 g· kg- 1 ·min- 1 was initated 30 min before spinal ischemia and continued for the subsequent 1 h reperfusion in group Ⅲ (E).In groups S and I/R the animals received equal volumes of NS instead of lidocaine.Neurological behavior was assessed according to Tarlov scoring system at 24 and 48 h of reperfusion.The lumbar segment ( L4、5 ) spinal cord was resected at 24 and 48 h ofreperfusion for microscopic examination.The expression of HIF-Ia in spinal cord was detected by immunohistochemistry analysis.ResultsCompared with group S,the expression of HIF-Iα in spinal cord was down-regulated,and Tarlov score was significantly decreased in groups S and l/R.The spinal cord injury was attenuated in group E compared with group I/R.CondusionEsmolol infusion can protect the spinal cord against I/R injury,and inhibition of the expression of HIF-1α is involved in the mechanism.
