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(P0.01). 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.