Study On The Mechanism Of Nerve Function Reconstruction After Naoxintong Treatment In Experiment Cerebral Ischemic Rat

Objective: To observe the neurological function scores and the expression ofBrdU positive cells and Nestin at different time after ischemia-reperfusion injury inSD rats. And to explore the proliferation of endogenous neural stem cell and the nervefunction reconstruction with Naoxintong treatment after cerebral ischemia.Methods:136healthy male SD rats aged7-8weeks and weighing250-300gwere enrolled in this study. Middle cerebral artery occlusion (MCAO) model wasconstructed with suture method. These rats were randomly divided into four groups:pseudo-surgery group, MACO group, MACO+low dose of Naoxintong group,MACO+high dose of Naoxintong group. Neurological function scores and infarctvolume were assessed on3th,7th,14th and21th day after cerebral ischemia andreperfusion. The proliferation of endogenous neural stem cell was checked by BrdUand Nestin through immunohistochemical staining after Naoxintong treatment. TheBrdU positive cells and Nestin were calculated by mean fluorescence intensity values.Results: The three experiment groups all showed vary degrees of neurologicalfunction deficit except for pseudo-surgery group. Neurological function scores weredecreased along with time, further neurological function scores at different time weresignificant in experiment groups (P<0.01). There is significant difference betweendifferent doses Naoxintong groups and MACO group (P<0.05). While high and lowdose of Naoxintong group showed no significant difference (P>0.05). Rat infarctvolumes assessed with2,3,5-triphenyltetrazolium chloride (TTC) in differentexperiment group were both highest on7thday after ischemia reperfusion by TTCstaining, and there were different significance at different time(P<0.05). The infarctvolumes were statistically significant difference among high dose Naoxintong, lowdose Naoxintong, and MACO model (P<0.01).(2) The expression of BrdU positivecells and Nestin could be observed on the3th days at the hippocampal denatate gyrusgranule lower (SGZ) and subependymal zone (SVZ) among MACO group, high doseNaoxintong, low dose Naoxintong groups. Immportantly, mean fluorescence intensity values were at highest level on7thday in these three groups, and showed graduallydecreased with time. The mean fluorescence intensity values of BrdU positive cells andNestin were statistically significant difference between different time（P<0.01）, whilethere were no significant difference between experiment groups (P>0.05).Conclusion:(1) Naoxintong could improve neurological function scores andreduce the infract volume, while the effect on neurological function dose not correlatewith dose of Naoxintong after ischemic reperfusion.(2) Endogenous stem cellsshowed reactive proliferation at the hippocampal denatate gyrus granule lower (SGZ)and subependymal zone (SVZ) after ischemic reperfusion. Mean fluorescence intensityvalues of BrdU positive cells and Nestin were at highest level on7thday in experimentgroups, and showed gradually decreased with time.(3) Naoxintong does not promotethe proliferation of endogenous stem cells at SVZ and SGZ.