Effect Of Lower Thoracic Epidural Block On Epithelial Apoptosis In Intestinal Mucosa Of Rats With Hemorrhagic Shock And Resuscitation

Objective:To investigate the effect of lower thoracic epidural anesthesia on apoptosis in intestinal mucosa of rats with hemorrhagic shock and resuscitation.Methods:Thirty-two SD rats with lower thoracic epidural catheter were selected,and randomly assigned to 4 groups(n=8 each): Sham group(sham operation),HSR group(hemorrhagic shock and resuscitation),NS group(hemorrhagic shock and resuscitation + epidural 0.9% normal saline100 μl/kg),and TEA group(hemorrhagic shock and resuscitation + epidural ropivacaine 100 μl/kg).The hemorrhagic shock was replicated according to the method described by Wiggers.Rats were resuscitated by transfusing shed blood and normal saline 60 min after hemorrhagic shock.Hemodynamic changes including MAP and HR after epidural catheterization,after epidural intervention,during shock,as well as 30,60,and 120 min after resuscitation were monitored.Blood loss and pH during shock and 120 min after resuscitation were recorded.Immunohistochemistry was applied to identify the expression of intestinal epithelial malondialdehyde(MDA),superoxide dismutase(SOD),Bax,Bcl-2 protein.Apoptosis index was calculated by Tunel 3 h after resuscitation.Results:Compared with HSR and NS group,pH was markedly increased during shock in TEA group(P < 0.05).And there was no statistical difference on the blood loss in the four groups except Sham group(P > 0.05).Compared with Sham group,intestinal epithelial MDA and Bax expression,as well as apoptosis index 3 h after resuscitation were significantly increased,while Bcl-2 expression was markedly decreased(P < 0.05).Compared with HSR and NS group,intestinal epithelial MDA and Bax expression,as well as apoptosis index were significantly decreased,while SOD and Bcl-2 expression was markedly increased in TEA group(P < 0.05).Conclusion:Lower thoracic epidural block protect the on intestinal epithelial cell via inhabiting lipid peroxidation and oxidative stress,up-regulating intestinal epithelial Bcl-2 and down-regulating Bax expression,then decreasing intestinal epithelial apoptosis in rats with hemorrhagic shock and resuscitation.