Neuroprotective effects of vascular endothelial growth factor following hypoxic ischemic brain injury in neonatal rats.

Vascular Endothelial Growth Factor (VEGF) protects the brain against ischemic injury in adult animals. We evaluated whether VEGF has neuroprotective effects against hypoxic-ischemic (HI) brain injury in newborn rats. Seven-day-old rat pups had the right carotid artery permanently ligated followed by 140 min of hypoxia (8% oxygen). VEGF (5, 10, 20, or 40 ng) or vehicle was administered intracerebroventricularly 5 min after reoxygenation following HI. Brain damage was evaluated by weight loss of the right hemisphere at 22 d after HI and by gross and microscopic morphology. Body weight, rectal temperature, and mortality were not significantly different in the VEGF and vehicle treated groups. VEGF treatment increased brain VEGF levels at 15 min after injection. VEGF (10 and 20 ng) significantly reduced brain weight loss (p < 0.05) and gross brain injury (p < 0.05); however, treatment with 5 or 40 ng did not. VEGF (10 ng) also decreased brain damage assessed by histologic scoring. VEGF increased phosphorylation of protein kinase B (Akt) and extracellular-signal regulated kinase 1/2 (ERK1/2) in the cortex (p < 0.05). These results suggest that VEGF has neuroprotective effects in the neonatal rat HI model that may be related to activation of the Akt/ERK signaling pathway.