Establishment And Application Of Cerebral Ischemic Stroke Model In Mice

Objectives: Successfully establised a cerebral ischemic stroke animal model isaffected by many factors. Infarct variation coefficient (IVC) due to a gradualexpansion of the lesion within a limited territory is an important indicator toevaluate the effect of ischemic stroke animal model. If the range of cerebralinfarction lesion of the experimental animal model is too large or too small, it caninflunce the IVC and the mortality of experimental animals. A crucial issue in theinduction of experimental focal cerebral ischemia has been to achieve a low IVCvalue and a low mortality rate. We attempted to improve IVC and mortality byusing the3-vessel occlusion model and expected to produce a reliable preclinicalevidence for evaluating a variety of interventions to ischemic stroke. Alogliptinbenzoate (AGL) is a potent and highly selective inhibitor of DPP-4. It was usedfor the treatment of type2diabetes mellitus and it has the cardiovascularprotective effects. We use C57BL/6J mice to establish3-VO ischemic strokemodel to investigate the influence of AGL on focal cerebral ischemia mice.Methods: We use C57BL/6J male mice to introduce a new operation approach.We use the transtemporal fascia approach to expose the zygomatic arch, in whichthe fascia of the temporal muscle is cut. Retract the facial nerve together with theorbitozygomatic vein that runs dorsoparallel to the nerve, cut the muscle under thefascia horizontally, and expose the surfaces of the zygomatic bone. Then weremove the zygomatic arch and open the temporal bone with a microdrill. Wepermanently occluded the MCA and temporarily occluded bilateral CCAsimultaneously with clips for15min to establish the mice3-VO cerebral ischemicstroke model. In the subsequent experiment, analysis in the acute phase onprophylactic AGL treatment performed before ischemia. The chronic phase on theprophylactic AGL treatment analyzed seven days after ischemia. We studied the rCBF in mice after the prophylactic treatment with AGL. We also analysed theeffect of prophylactic AGL treatment on infarcted lesion volumes andneurological deficits. Determination of BDNF levels after the prophylactic AGLtreatment and the effect of post hoc AGL treatment on volumes of infarctedlesions and neurological deficits were determined.Results: We successfully established3-VO ischemic stroke model in mice. Theapproach of this ischemic stroke model avoided traumatic venous bleeding aroundthe zygomatic arch and we can get a reliable and repeatable ischemic penumbra inthe cerebral cortexes of mice. This3-VO ischemic stroke model in mice canreduce the rCBF consistently within the ischemic penumbra. The model canreduce IVC, and it can reduce the mortality after ischemia. We expected toproduce reliable preclinical evidence in the assessment of neuroprotectiveinterventions for ischemic stroke. There were no significant differences in bodytemperature, heart rate, mean arterial blood pressure, body weight and bloodglucose between vehicle and the three different AGL treated groups during theoperative period. AGL has protective effect on ischemic stroke in mice.Conclusions: We use3-VO to establish a new cerebral ischemic stroke model inmice. The model needs more shorter operation time, the IVC value is more lowerand the mortality after infarction is also reduced. The3-VO cerebral ischemiaanimal model of our team can produce a coherent, consistent ischemic penumbra.We can use this3-VO ischemic stroke animal model to explore the treatment andprotection of ischemic stroke. It was demonstrated that chronic, prophylactictreatment with AGL increased BDNF levels in the brain, and protected the brainagainst ischemic stroke. AGL has protective effect on focal cerebral ischemia inmice. AGL might be useful as a neuro protectant, or an enhancer of BDNFproduction in the brain, aiming to prevent or minimize brain injury due to primaryor recurrent ischemic stroke.