| Purpose:The cascade reaction played an important role in determining neuronal integrity of structure and normal function after cerebral ischemia and reperfusion which involved a lot of links such as production of oxygen free radicals,intracellular overload of calcium,toxicity of excitatory amino acid,inflammatory reaction and apoptosis of neuronal and endothelial cells.Clinical application of single neuroprotective agents was limited because a single neuroprotective agent which aimed at a single link couldn't completely and effectively block the cascade reaction after cerebral ischemia and reperfusion while they had severe dose-ralated toxic and adverse effects.Combined use of neuroprotective agents was becoming a focus of investigation.The neuroprotective effects and mechanisms in our study were investigated by observing:(Dthe effects of combined use of MK-801 (antagonist of NMDA receptor),NAC(radical scavenger) and defibrinogenase on the infaction volume,the apoptosis of neuronal and endothelial cells,the expression of Bcl-2,MAP-2 and the content of ET-1 in plasma after focal cerebral ischemia and reperfusion;(2)the effects of combined use of mannitol(radical scavenger) and nimotop(antagonist of calcium)on the apoptosis of neuronal cells and the contents of MDA and NO after focal cerebral ischemia and reperfusion;(3)the effectsof combined use of ligustrazine(activating blood drug) and astragus(reinforcing Qi drug) on the activity of MPO and contents of TNF- a , IL-1B after focal cerebral ischemia and reperfusion. Methods:The string inserting method through extrenal carotid artery that accords to Longa s report was employed to make the model of focal cerebral ischemia and reperfusion. (1)Make the models of focal cerebral ischemia 2h and reperfusion 6h, 24h. The experimental animals were divided into TTC and ET-1 group,TUNEL and MAP-2 group,Bd-2 group; furthermore the rats in every group were randomly subdivided into sham-operated group,model group,MK-801 group,NAC group,defibrinogenase group and combined use of MK-801,NAC and defibrinogenase group.The methods of coloration of TTC (2,3,5-triphenylteterazolium chloride) and RIA (radioimmuno-assays) were used respectively to measure the infarct volume and the content of ET-1 in plasma;the method of TUNEL was used to measure the apoptosis of neuronal and endothelial cells;the methods of immunohistochemistry and MIPS were used to measure positive cells of Bcl-2 and MAP-2 proteins.(2) Make the models of focal cerebral ischemia 2h and reperfusion 24h.Rats were randomly divided into sham-operated group,low-dose mannitol group,high-dose mannitol group,nimotop group and combined use of low-dose mannitol and nimotop group.The methods of fluorescence labelled TUNEL, coloration of thiobarbiturate and nitrate redutase were respectively used to measure apoptosis of neuronal cells and the contents of MDA and NO. (3) Make the models of focal cerebral ischemia 2h and reperfusion 6h, 24h.Rats were randomly divided into sham-operated group,model group,ligustrazine group,astragus group and prescript of ligustrazine and astragus group.The methods of RIA, ELISA(enzyme linked immuno-sorbent assay) andpectrophotometry were respectively used to measure the content ofTNF- a , IL-1B and the activity of MPO in rat' brains.Result:1.The infarction volumn of rats' brains in ischemia sides of model group was 219.7 + 26. lmm'.Infarction volumns of rats' brains in MK-801 group,NAC group,defibrinogenase group and combined use of them group respectively were 129.1 + 25. 8mm3,140.3 + 21. 5mm3,122.2 + 23. 6mm3 and 91.2 + 11. 7mm3 which decreased significantly, compared with that in model group(P<0.01). Compared with that in MK-801 group,NAC group and defibrinogenase group respectively, infarction volumn of rats' brains in combined use of them group was the smallest (P<0.05).Compared with those in sham-operated sides of sham-operated group,the number of positive neuronal cells of TUNEL and Bcl-2 protein increased while the mean grey level of Bcl-2...
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