血小板源性生长因子受体-β在蛛网膜下腔出血后脑血管痉挛中的作用

The effect of platelet derived growth factor receptor-β on the cerebral vasospasm after subarachnoid hemorrhage in rabbit

目的观察兔蛛网膜下腔出血(SAH)后基底动脉的血小板源性生长因子受体-β(PDGFR-β)的表达变化规律,从侧面反映血小板源性生长因子(PDGF)-BB在SAH后脑血管痉挛(CVS)的作用。方法采用枕大池二次注血法建立稳定的兔CVS模型,应用HE染色、透射电镜、免疫组化技术等方法,观察兔基底动脉的超微结构变化及PDGFR-β的表达时间窗,并通过测量管径的变化来判断CVS的严重程度。结果电镜结果提示SAH组的基底动脉部分内皮细胞脱落,紧密联接打开,内皮间隙扩大;内弹力膜扭曲、断裂;平滑肌细胞胞浆空泡状,排列紊乱;外膜可见大量中性粒细胞、单核细胞浸润;管腔狭窄呈急性期收缩和迟发性痉挛双相改变;免疫组化结果提示对照组的PDGFR-β无阳性表达,SAH组的PDGFR-β表达升高,在第5、7天时最为明显(P<0.01),第10天后表达稍下降,但仍高于对照(P<0.05)。结论 PDGFR-β在SAH后CVS中基底动脉的表达呈现一定的时序性,提示PDGF-BB在迟发性脑血管痉挛的发生发展中起作用。

Objective To observe the expression of platelet derived growth factor receptor-IS （PDGFR- β） in the basilar arteries after subarachnoid hemorrhage （SAH） in rabbits, which partly reflected the effects of platelet derived growth factor （PDGF）-BB on the cerebral vasospasm（CVS） after SAH. Methods A steady model of CVS after SAH in rabbits was produced by two-time blood injection of autologous arterial blood into the cistema magna. HE staining, transmission electron microscope （TEM） and immunohistochemical technique were respectively used to observe the uhrastructural changes and the expression of PDGFR-β in the vessel walls of basiliar artery. The diameter of each basilar arterial lumen was measured to evaluate the degree of CVS. Results The results of TEM in SAH groups showed some uhrastructural changes in basiliar artery, including desquamation of partial endothelial ceils, the tight junction＇s open, the expansion of endothelial gap, the distortion and disruption of internal elastic lamina, disordered arrangement in smooth muscle cells of cytoplasmic vacuolization, and the infiltration of abundant neutrophilic granulocyte and monocyte in adventitia. This model showed biphasic patterns to the luminal narrowing：acute constriction and delayed vasospasm phase. The expression of PDGFR-β in control groups was negative, while the expression in SAH groups was positive, and it was the most significant expression in 5 and 7 days after SAH（P 〈0. 01 ）, and decreased 10 days after SAH, but it was still significantly higher than that in control group （P 〈 0. 05 ）. Conclusion The expression of PDGFR-β showed the regular change in time course in the basiliar arteries after SAH, which suggested that PDGF-BB was important significance in the course of occurrence and development after CVS.