The Expression Of P38 MAPK MRNA And ERK 1/2 MRNA In Brain Protection Of Rats Induced By Limb Ischemic Preconditioning

Objective: The purpose of the study is to explore the expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain protection of rats induced by limb ischemic preconditioning(LIP).In order to observe the expression of p38 MAPK mRNA and ERK 1/2 mRNA in the hippocampal CA1 region,we use Real-time PCR technology.Method:1.The expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain ischemic tolerance of rats induced by LIP.Ninety Wistar rats whose bilateral vertebral arteries were blocked permanently were randomly divided into sham,brain ischemia(BI)and LIP+BI groups.The rats were killed by decapitation at time points of 0 h,6 h,12 h,1 d and 2 d after sham operation or BI in each group.2.The influence of the transection of femoral nerve and sciatic nerve on the expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain ischemic tolerance induced by LIP.The forty-five Wistar rats whose bilateral vertebral arteries were blocked permanently were randomly divided into sham,BI,LIP+BI,femoral nerve transection(FNT)+BI,FNT+LIP+BI,sciatic nerve transection(SNT)+BI,SNT+LIP+BI,FNT+SNT+BI and FNT+SNT+LIP+BI groups.According to the results of Part 1,rats were killed by decapitation and taken from the hippocampal CA1 tissue at 12 h after the sham operation or brain ischemia in each group.3.The influence of the free radical scavenger on the expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain ischemic tolerance induced by LIP.The twenty-five Wistar rats whose bilateral vertebral arteries were blocked permanently were randomly divided into sham,BI,LIP+BI,DMTU+LIP+BI and DMTU+sham groups.The rats of each group were killed by decapitation and taken from the hippocampal CA1 region at 12 h after the sham operation or BI in each group.4.The expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain ischemic tolerance induced by LIP in the adenosine(Ade)pathway.1)The influence of adenosine A1 receptor antagonist on the expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain ischemic tolerance induced by LIP.The twenty-five Wistar rats whose bilateral vertebral arteries were occluded permanently were randomly divided into sham,BI,LIP+BI,DPCPX+LIP+BI and DPCPX+sham groups.2)The influence of Adenosine(Ade)on the expression of p38 MAPK mRNA and ERK 1/2 mRNA in hippocampal CA1 region of brain ischemic rats.The twenty Wistar rats whose bilateral vertebral arteries were occluded permanently were randomly divided into sham,BI,Ade+BI and Ade+sham groups.Results:1.The expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain ischemic tolerance of rats induced by LIP.Compared with the BI 0 h group,the mRNA expression of p38 MAPK and ERK 1/2 was up-regulated at 6 h in LIP+BI group and peaked at 12 h.Then the mRNA expression returned to BI 0 h levels gradually.The above findings indicated that the expression of p38 MAPK mRNA and ERK 1/2 mRNA were significantly up-regulated in the BI group 12 h.2.The influence of the transaction of femoral nerve and sciatic nerve on the expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain ischemic tolerance induced by LIP.Compared with the LIP+BI group,the up-regulation in p38 MAPK mRNA and ERK 1/2 mRNA was significantly inhibited in FNT+LIP+BI,SNT+LIP+BI and FNT+SNT+LIP+BI groups.These results demonstrated that LIP up-regulated the expression of p38 MAPK mRNA and ERK 1/2 mRNA partly through femoral nerve and sciatic nerves pathway.3.The influence of the free radical scavenger on the expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain ischemic tolerance induced by LIP.Compared with the LIP+BI group,the up-regulation of p38 MAPK mRNA and ERK 1/2 mRNA was significantly inhibited in DMTU+LIP+BI group.The above results shown that LIP up-regulated the mRNA expression of p38 MAPK and ERK partly through the free radical pathway.4.The expression of p38 MAPK mRNA and ERK 1/2 mRNA in brain ischemic tolerance induced by LIP in the adenosine(Ade)pathway.Compared with the LIP+BI group,the up-regulation of p38 MAPK mRNA and ERK 1/2 mRNA was significantly inhibited in DPCPX+LIP+BI group.Compared with the BI group,the expressions of both p38 MAPK mRNA and ERK 1/2 mRNA were obviously up-regulated in Ade+BI group.These findings indicated that adenosine was involved in up-regulation of p38 MAPK mRNA and ERK 1/2 mRNA in hippocampal CA1 region.Conclusions:LIP partly up-regulates the mRNA expression of p38 MAPK and ERK through femoral nerve and sciatic nerve,free radical,and adenosine pathways,and plays a neuroprotective role in rats.