The effects of calcitonin gene-related peptide on bFGF and AQP4 expression after focal cerebral ischemia reperfusion in rats

The aim of this study was to investigate whether calcitonin gene-related peptide (CGRP) administration could produce neuroprotective effects after brain ischemia reperfusion in rats. Brain ischemia reperfusion injury was induced by a 2-hour left middle cerebral artery occlusion (MCAO) using an intraluminal filament, followed by 46 hours of reperfusion. CGRP (1 μg/ml) at the dose of 3 μg/kg, i.p., was administered at the beginning of reperfusion. Saline (3 ml/kg body weight) treated animals were used as control. Sham-operated animals were also used. Subsequently, 48 hours after MCAO, infarct volume, histological alterations, based fibroblast growth factor (bFGF) and aquaporin-4 (AQP4) expression were examined. The results showed that CGRP could significantly decrease infarct volume, improve brain tissue histological damage, promote bFGF expression and inhibit AQP4 expression after brain ischemia reperfusion injury. The results suggested that the neuroprotective effects of CGRP may be mediated by promoting bFGF expression and inhibiting AQP4 expression. The spatial and temporal distribution of molecules involved in the ischemic cascade by CGRP administration should be further studied.