大鼠蛛网膜下腔出血后迟发性脑血管痉挛和rHSG表达相关性的实验研究

目的 探讨大鼠蛛网膜下腔出血(SAH)后迟发性脑血管痉挛(DCV)和大鼠增殖抑制基因(rHSG)表达之间的关系.方法 SD大鼠156只,随机分为SAH组(A组)、生理盐水组(B组)和正常对照组(C组).A组采用枕大池二次注血法诱发;B组同法注射等量生理盐水.A、B组分别在4、7、10、13、16、20d取基底动脉(BA)行HE染色后测量其内径周长、血管壁厚度,观察血管结构改变;免疫组化检测BA rHSG蛋白;RT-PCR法检测BA中rHSG mRNA.结果 B、C组BA血管结构正常,无DCV发生;A组第4天出现DCV,第7天达到高峰,高峰期持续至第10天.后逐渐缓解,20d趋于正常.A组除20d外,各时相BA有不同程度的内膜增厚皱折、平滑肌层增厚等增殖性改变.与B组及C组相比,A组4～16d rHSG蛋白及rHSG mRNA表达均降低(P<0.05),第7天显著降低(P<0.05).结论 SAH后DCV的发生和严重程度与血管壁增生程度及rHSG低表达密切相关.

Relationgship between expression of rHSG and delayed cerebral vasospasm after experimental subarachnoid hemorrhage in rats

Objective To explore relationship between expression of rats hyperplasia suppresion gene(rHSG)and delayed cerebral vasospasm(DCV)after experimental subarachnoid hemorrhage(SAH).Methods 156 Sprague-Dawley rats were randomly divided into SAH group(n=72),saline-control group(n=72)and normal control group(n=12).SAH was developed with twice injections of 0.3 ml arterial blood into cisterna magna,and 0.3 ml saline injected for saline-control group.For SAH group and saline-control group,the basilar arteries(BA)were harvested on 4d,7d,10d,13d,16d and 20d after experiments.BA were stained by hematoxylin-eosin for measurements of perimeter,wall thickness and observation of structures respectively.Proteins of rHSG in BA was evaluated by immunohistochemically staining.Expression changes of rHSG mRNA in the BA were identified by RT-PCR.ResIlJts For saline-control group and normal control group.there were no structural changes and DCV of BA at different time points.For SAH group,DCV appeared on 4d after the first cisterna magna injection and reached the peak on 7d.The peak of vasospasm continued until 10d and then gradually diminished, and artery diameter returned to the normal control diameters on 20d.The luminal narrowing,increased wall thickness,and corrugation of the tunica intima in arteries can be seen from 4d to 20d after SAH.The expression of rHSG protein and mR-NA decreased at different time points of SAH group compared with saline-control group and normal group(P<0.05),and significantly diminished on 7d than other times after SAH(P<0.05).Conclusion Our results suggested that the lowly expression of rHSG and vascular cell proliferation in the BA of rat may be associated with the delayed cerebral vasospasm.