降钙素基因相关肽与内皮素受体A在兔实验性蛛网膜下腔出血后基底动脉的表达

Expression and significance of CGRP and ETRA in the basilar artery after subarachnoid hemorrhage in a rabbit model

目的探讨蛛网膜下腔出血(SAH)后脑血管内皮细胞降钙素基因相关肽(CGRP)及内皮素受体A(ETRA)的表达与迟发性脑血管痉挛(DCVS)之间的关系。方法日本大耳白家兔60只,随机分为SAH模型组25只,盐水组25只,穿刺组5只,正常组5只。采用枕大池二次注血法制作SAH模型,灌注处死后取基底动脉制成切片。进行CGRP及ETRA的免疫组化和HE染色,观察CGRP与ETRA的免疫表达和病理结构变化,并用图像分析方法测量血管周长,使用方差分析进行统计学检验。结果基底动脉周长在SAH后均发生明显缩窄,其中在5d时缩小最强烈。CGRP与ETRA免疫阳性标记颗粒在SAH组的基底动脉组织中均有表达,其动态变化规律为CGRP的表达在1h时最明显,在3、5d依次表达减少,5d达到最低点,7d后开始逐渐升高,10d时表达相对比较明显,但未能达到正常水平,CGRP在穿刺组、正常对照组和盐水组也有散在不规则表达。在正常组、穿刺组和盐水组的基底动脉内ETRA有表达;SAH组基底动脉内ETRA在3d组和5d组表现为高表达,以3d组为强,而其中血管内皮细胞表达最强烈,平滑肌也有表达,10d组的表达仍然较强。结论在SAH后脑血管内皮细胞CGRP和ETRA的表达呈现明显的动态改变,但二者的变化趋势并不同步;CGRP和ETRA在DCVS的发生发展中起重要的作用。

Objective To discuss the relationship between the expression of calcitonin gene-related peptide （CGRP） and endothelin receptor A （ETRA） in the cerebral vessels cells with delayed cerebral vasospasm after subarachnoid hemorrhage （SAH）. Methods A total of 60 Japanese white rabbits were randomly divided into four groups： 25 in SAH group, 25 in normal saline group, 5 in puncture group and 5 in normal group. An experimental SAH was induced by intracistcrnal injection of arterial blood in rabbits. The animals were sacrificed for perfusion fixation and the basilar arteries were made in paraffin section. The basilar arteries were removed for immunohistochemistry and HE staining, and then the immunohistochemical expression and changes of pathological structure were observed. We used image analysis system to measure the vessel perimeter and ANOVA for statistical analysis. Results The anteroposterior perimeter of basilar arteries was obviously coarctated after injecting arterial blood; there were CGRP and ETRA immunohistochemical positive staining granula expressions in the basilar artery tissues. Its dynamic change regularity was as follows： the expression of CGRP was the most obvious at 1 h, and decreased from day 3 to day 5 by turns, then on days 5 reached the lowest; it began to increase from day 7, the expression on day 10 was relatively obvious, but did not reach the normal level. There was scattered irregular positive staining in the normal saline group and puncture group. ETRA was expressed on the basilar artery both in blank group and puncture group. They were expressed mainly on the vascular endothelial cells. ETRA was also expressed on the basilar artery in the saline group. ETRA was expressed heavily on the basilar artery＇s endothelial cells in SAH group, mainly in 3-day subgroup. Smooth muscle cells also expressed ETRA. Conclusion The expression of CGRP and ETRA in the cerebral vessel ceils after subarachnoid hemorrhage presents obviously dynamic changes; and it is suggested that CGRP plays a very important role in the delayed cerebral vasospasm.