ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of vasoactive intestinal peptide (VIP) on angiogenesis after focal cerebral ischemia.</p><p><b>METHODS</b>Focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 120 min in adult SD rats with intracerebroventricular VIP administration at the beginning of reperfusion. Immunohistochemistry was performed to assay BrdU immunoreactive endothelial cells, expressions of VEGF, flt-1 and flk-1 in the ischemic zone, and the protein expressions of vascular endothelial growth factor (VEGF) in the brain was measured using Western blotting.</p><p><b>RESULTS</b>Immunohistochemical staining revealed significantly increased BrdU immunoreactive endothelial cells on the margins of the ischemic lesion in rats treated with VIP as compared with that in the control rats (P<0.05). VIP significantly increased the number of VEGF immunoreactive cells and flt-1- and flk-1-positive endothelial cells in comparison with the control group (P<0.01). Western blotting showed that VIP treatment resulted in significantly increased VEGF protein level in the ipsilateral hemisphere (P<0.05).</p><p><b>CONCLUSIONS</b>VIP enhances angiogenesis in the ischemic brain by increasing the expressions of VEGF in the brain tissue and its receptors flt-1 and flk-1 in the endothelial cells.</p>
Subject(s)
Animals , Male , Rats , Brain , Metabolism , Brain Ischemia , Allergy and Immunology , Metabolism , Pathology , Endothelial Cells , Metabolism , Gene Expression Regulation , Neovascularization, Physiologic , Rats, Sprague-Dawley , Vascular Endothelial Growth Factor A , Metabolism , Vascular Endothelial Growth Factor Receptor-1 , Metabolism , Vascular Endothelial Growth Factor Receptor-2 , Metabolism , Vasoactive Intestinal Peptide , PharmacologyABSTRACT
<p><b>OBJECTIVE</b>To explore the neuroprotective effect of vasoactive intestinal peptide (VIP) in rat ischemic brain injury.</p><p><b>METHODS</b>VIP was administered via intracerebroventricular injection in SD rats prior to focal cerebral ischemia by intraluminal occlusion of the middle cerebral artery. The infarct volume was assessed with TTC staining, and immunohistochemistry was performed to analyze the S100beta expression in the cerebral tissue, with the serum concentrations of S100beta detected by double-antibody sandwich enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>After VIP injection, the relative infarct volume in the rats with cerebral ischemia was significantly reduced by 32.3% as compared with the volume in the control group on day 1 (P<0.05), and the number of S100beta-positive cells was significantly decreased in the cerebral tissue (P<0.05). The injection also resulted in significantly decreased serum S100beta concentrations in the rats (P<0.05).</p><p><b>CONCLUSION</b>VIP injection can reduce the infarct volume in rats with focal cerebral ischemia, suggesting the neuroprotective effect of VIP in brain ischemia possibly by reducing S100beta overexpression.</p>