Roles Of P38PAPK、Bcl-2in Neuroprotection Induced By Abdominal Surgical Incision Remote Preconditioning Of Trauma In MCAO Rats

Objective:To explore the neuroprotective effect of the remote preconditioning of trauma (RPCT) on cerebral ischemia-reperfusion injury. To investigate whether P38MAPK and Bcl-2involved in the cerebral protection induced by remote preconditioning of trauma in middle cerebral artery occlusion model in rats.Methods:Part I Seventy adult male Sprague-Dawley rats were divided randomly into seven groups (n=10, each). Neurological deficit scores of all the rats were evaluated by methods of Longa’s and Garcia’s once a day from3days before the surgery. Take the average of the three scores as the preoperative neurological deficit score,①sham group:Only separate the right side of the neck vessels, without ligation of the middle cerebral artery;②ischemia-reperfusion (I/R group):MCAO model is adopted to establish the rats with focal cerebral ischemia reperfusion model on the right side;③RPCT groups:Abdominal incision was made30min、1h、2h、4h、24h before occluding the middle cerebral artery as the nonischemic stimulus for the RPCT. The incision was through the skin, subcutaneous, fat, muscle and peritoneum, and was2cm in length through the abdominal midline. Afterward the incision was sutured immediately. Middle cerebral artery occlusion was for90minutes. At24h after middle cerebral artery reperfusion the neurological deficit scores (NDS) and cerebral infarct size by TTC staining were evaluated.Part II Forty adult male SD rats were divided randomly into four groups(n=10, each):sham group, I/R group,1h RPCT group and24h RPCT group. The rats of the four groups were given the same treatment as Part Ⅰ. At24h after reperfusion, the NDS were evaluated by the methods of Longa’s and Garcia’s. Five rats of each group randomly were selected to be observed brain tissue morphology by HE staining^Nissl staining and measured the expression of P38MAPK、p-P38、Bcl-2via immunohistochemistry analysis. Another five rats of each group were measured the expression of the three proteins via Western Blot.Results:Part Ⅱ1.TTC staining:The cerebral infarct was not observed in the sham group. There was no difference between the infarction size in I/R group and in30min RPCT group (P>0.05).The infarction sizes in the other RPCT groups were significantly smaller than that in I/R group (P<0.05).2.The NDS of the Longa method were no significant difference between the I/R group and all RPCT groups, but the NDS in RPCT groups except the30min RPCT group of the Garcia method were significantly higher than that in I/R group(P<0.05).Part Ⅱ l.The NDS of the Longa method were no significant difference between the I/R group and RPCT groups, but the NDS of the Garcia method in RPCT groups were significantly higher than in I/R group(P<0.05)).2. HE staining:The neurons in the sham group were eumorphism. The neurons in the core area in I/R group and RPCT groups were scarce and the tissue were loose. Compared with that in I/R group, the neurons in the penumbra cortex in RPCT groups were more clear and the morphology were more complete. The interstitial edema was alleviative in penumbra cortex in RPCT groups.3. Nissl staining:Normal morphological characteristics of neurons showed in sham group. The number of the survival neurons in the penumbra cortex significantly increased in RPCT groups than that in I/R group (P<0.05)).4. Immunohistochemical analysis and western blotting:The expression of P38MAPK didn’t change significantly among the sham、I/R and RPCT groups (P>0.05)). Compared with I/R group, in RPCT groups the expression of p-P38and Bcl-2protein in the penumbra cortex significantly increased (P<0.05).Conclusions:1. The remote preconditioning of trauma possesses neuroprotective effect against the focal cerebral ischemia-reperfusion injury.2. It may be related to the increase of P38MAPK phosphorylation and the up-regulation of Bcl-2that the cerebral protection induced by the remote preconditioning of trauma.