The Neuro Protection Of Remote Ischemic Postconditioning Of Brain Ischemic Postconditioning On Cerebral Ischemic Injury In Rats

Objectives To establish animal modle of focal cerebral ischemic and to investigate theprotective effect and mechanism of noninvasive ischemic postconditioning againstacute focal cerebral ischemic injury in rats.Methods A total of90adult, healthy, male, Sprague-Dawley rats (260g~280g), wererandomly divided into5groups,18in each group. Besides Sham group, the latter fourgroups were established with focal cerebral ischemic by an intraluminal thread middlecerebral artery occlusion for2h.1Sham surgery group: simply exposing blood vessels,no operation.2I/R Group: MCAO2h, no non-invasive RPC.3IP Group: after2h ofMCAO at the beginning of reperfusion, postconditioning was performed as3cycles of20seconds reperfusion (withdrawing the nylon5mm)/20seconds ischemia (inserting thenylon5mm).4I-RPC Group: after2h of MCAO at the beginning of ischemic, non-invasive RPC was performed.5R-RPC Group: after2h of MCAO at the beginning ofreperfusion, non-invasive RPC was performed. Non-invasive RPC methods:3cycles of10min noninvasive limb ischemic (occluding the bilateral femoral artery by tourniquets),then10min reperfusion (releasing the tourniquets). The models were evaluated withexaminating neurologic deficit scores (Longa standard), infarct volume (TTC staining),water content (wet and dry weighing method) and morphology (HE dyed) at24h afterreperfusion. Meaning the time, the rat hippocampal apoptosis cells were tested byTUNEL method and the levels of Hs-CRP positive expression were tested byimmunohistochemical method.Results1The ischemic reperfusion models in the rats were successfully established byintraluminal suture method;2Compared with the I/R group, the IP group, I-IPC groupand R-RPC group showed the neurobehavioral function deficit scores was decreased(P<0.05), the infarct volume was reduced (P<0.05), the brain water content was reduced(P<0.05), and the pathology change were improved (P<0.05), the numbers of apoptosiscell decreased significantly (P<0.05) and the level of Hs-CRP decreased significantly(P<0.05), but there were no significant difference among IP group, I-IPC group, and R-RPC group(P>0.05).Conclusions The modified MCAO modle is a cerebral ischemic tolerance modle with favorable stability; the method of noninvasive limb ischemia were proved to have aneural protection role. The protectional mechanism may be related to lower the levels ofapoptosis and Hs-CRP. It provides new ideas and means for clinical treatment of acutecerebral ischemic disease.