脑缺血再灌注中PDGF-BB和TGF-β1表达变化的试验研究

Tentative study of expression changes of PDGF-BB and TGF-β1 in cerebral ischemia reperfusion

目的探讨血小板衍生生长因子BB(PDGF-BB)在缺血再灌注(MCAO/R)中的功能及其与转化生长因子β-1(TGF-β1)的表达关系。方法制备大鼠脑缺血再灌注模型,分为假手术组(A组)、缺血再灌注组(B组),缺血2h后依照再灌注时间的不同分为0h、6h、12h、24h、48h、3d及7d共6组,另设缺血2h后再灌注24h(MCAO2h/R24h)促红细胞生成素干预组(C组),TTC染色组测量缺血灶体积(D组)。A、B、C组各时相点取材,免疫组化显示脑PDGF-BB及TGF-β1的表达变化并进行定量分析。结果MCAO2h组缺血灶体积最小,再灌注后增加,第3天时达到高峰,第7天时有所减小。药物干预组较无干预组缺血灶体积减小。PDGF-BB在假手术组、MCAO2h组阳性表达无差异;随再灌注时间延长表达增加,7d后达高峰;药物干预组与无干预组相比阳性表达增多。TGF-β1在MCAO2h组较假手术组阳性表达减低;再灌注6h后表达开始增多,48h达高峰,并持续至第7天;药物干预组与无干预组相比阳性表达增加。结论脑缺血/再灌注损伤可以诱导PDGF-BB和TGF-β1表达,促红细胞生成素可以增加这两个生长因子的表达,起到神经保护作用。

Objective To observe the function ofplatelet-derived growth factor BB （PDGF-BB） in cerebral ischemia reperfusion （MCAO/R） and the expressive relation between PDGF-BB and TGF-β1. Methods Prepare rat subjects of cerebral isehemia reperfusion. Rats were divided into sham operation group （group A）, isehemia reperfusion group （group B）. Two hours after isehemia the isehemia reperfusion group is divided into 6 subgroups according to reperfusion time difference as 0 h, 6 h, 12 h, 24 h, 3 d and 7 d. Two hours after isehemia by reperfusing 24 h （MCAO 2 h/R 24 h） to form a group of somatotrophie erythrocyte production intervention （group C） and TTC staining group measuring ischemia volume （group D）. Material was taken from group A, B and C in different time and place to analyze expressive changes of brain PDGF-BB and TGF-β1 expressed by immunohistoehemieai quantitatively. Results The isehemia volume in MCAO 2 h was the least and expanded after reperfusion. It reached climax on the third day and reduced a little on the seventh day. The medicine intervention group almost did not intervene the reduction of ischemia volume. The expressions of PDGF-BB in sham operation group and MCAO 2 h group were almost the same. With the reperfusion went on, the expression grew more and it reached climax after 7 days. Medicine intervention group had more positive expression than non-interven.tion group. The expression in TGF-β1 was less positive than that in MCAO 2 h. It appeared to grow more 6 hours after reperfusion and reached climax after 48 hours. It remained until the seventh day. The expression of medicine intervention group was more positive than non-intervention group. Conclusion Ischemia and reperfusion injury can induce expression of PDGF-BB and TGF-β1. Somatotrophie erythrocyte production can promote the expression of such two factors to protect nerve.