降钙素基因相关肽对局灶性脑缺血再灌注大鼠海马Fas mRNA表达的调节作用

目的研究外源性降钙素基因相关肽(CGRP)对局灶性脑缺血再灌注大鼠海马Fas mRNA表达的影响,探讨降钙素基因相关肽对缺血再灌注脑神经组织的作用。方法用线栓法制备大鼠大脑中动脉阻塞(MCAO)模型,应用原位杂交和显微图象分析方法检测局灶性脑缺血再灌注大鼠海马Fas mRNA的表达。结果假手术组大鼠海马未见Fas mRNA阳性表达;缺血再灌注组(缺血再灌注不同时间段6 h,12 h,24 h,48h,72 h)海马Fas mRNA明显过表达;注射CGRP后海马区Fas mRNA阳性表达细胞平均光密度值明显低于缺血再灌注组(P<0.01)。结论经颈动脉注入外源性CGRP下调缺血神经元Fas mRNA的表达,可能是外源性CGRP对缺血神经元保护作用的机制之一。

The Effect of Calcitonin Gene Related Peptide on the Expression of Fas mRNA in the Hippocampus during Focal Cerebral Ischemia/Reperfusion in Rats

Objective To investigate the effect of exogenous calcitonin gene related peptide (CGRP) on the expression of Fas mRNA in rat hippocampus with focal cerebral ischemia/reperfusion(I/R) and to explore the effect and mechanism of CGRP on ischemia brain tissue. Methods Using middle cerebral artery occlusion (MCAO) to make focal cerebral ischemia model, the expression of Fas mRNA in hippocampus was detected with in situ hybridization method and analyzed by microimage analysis system. Results Fas mRNA positive cells were not found in hippocampus of sham group, but were found obviously in focal cerebral I/R group(6 h,12 h,24 h,48 h and 72 h after I/R). The average optical density(OD) value of Fas mRNA positive product in hippocampus of CGRP group was lower than that in I/R group(P<0.01). Conclusion Exogenous CGRP through carotid artery injection can downregulate the expression of Fas mRNA in ischemic neurons of hippocampus,which may be one of the mechanisms for the protective effect of the ischemic neuron by CGRP.