Neuroprotection Mechanism Of Lidocaine For Early Brain Injury In A Rabbit Model Of Subarachnoid Hemorrhage

Objective: To investigate the neuroprotection mechanism of lidocaine for early brain injury in a rabbit model of subarachnoid hemorrhage Methods: Eighteen New Zealand white rabbits were randomly divided into three groups: Sham group(Sham),Subarachnoid hemorrhage group(SAH)and Lidocaine group(LD).Subarachnoid hemorrhage animals models were injected fresh autologous arterial blood into the cisterna magna by a single blood injection method,All animals underwent operation under anaesthesia and tracheal intubation.1 mL/Kg autologous arterial blood was injected into cisterna magna in SAH group and LD group,and 1mL/Kg saline into cisterna magna in Sham group.After blood injection,the rabbit was kept in a prone position with the head tilted down 30° for Thirty minutes.Thirty minutes after SAH,0.3 mL 2 percent lidocaine was injected into cisterna magna in LD group,and equal-volume saline into cisterna magna in Sham group and SAH group,which was used breathe balloon to keep breathing and sent back to the animal experimental center after them awaked.72 hours after SAH all animals were assessed for the grade of food intake and neurological impairment,and killed.Then the Caspase-3 and Cyt-C mRNA expression in hippocampus was determined by RT-PCR,the Caspase-3 and Cyt-C protein expression in hippocampus was determined by Western Blot,and the positive expression of Caspase-3 and Cyt-C was observed with immunohistoehemistry by light microscopy.Results: Compared with sham group,there were lower grade of food intake and vary degrees of neurological impairment in the SAH and LD groups(P<0.05);Compared with SAH group,the grade of food intake and neurological impairment were not significantly different in LD group(P>0.05).Compared with sham group,it was higher expression levels of Caspase-3and Cyt-C mRNA with proteins in SAH and LD groups(P<0.05);Compared with SAH group,There were lower expression levels of Caspase-3 and Cyt-C mRNA with proteins in LD group(P<0.05).Compared with sham group,the positive expression of Caspase-3 and Cyt-C in other two groups was increased(P<0.05);Compared with SAH group,the positive expression of Caspase-3 and Cyt-C in LD groups was decreased(P<0.05).Conclusion: Neuroprotection mechanism of lidocaine on earlybrain injury in a rabbit model of subarachnoid hemorrhage may have relation with the inhibition activiting of mitochondrial pathway.