The Mechanism And Effect Of VEGF Expression In Tree Shrew Hippocampus Following Photochemistry Induced Thrombotic Cerebral Ischemia In The Treatment Of Different Brain-temperature

OBJECTIVE: To observe the change of vascular endothelial growth factor (VEGF) expression of different temperature(subhypothermia, normal temperature and hyperthermia) after cerebral thrombosis in hippocampus CAl area of Tree Shrew. To explore the mechanisms of VEGF expression in different Brain-temperature after cerebral thrombosis. To illuminate the effect of the temperature in thrombotic cerebral ischemia and provide the pathophysiologic clues for clinical hypothermia posttreamtent after cerebral ischemia. METHODS: The focal thrombotic cerebral ischemia was induced by photochemical reaction in tree shrews. Different temperature was initiate 6 hours after ischemia, temperature varied from subhypothermia(31℃ ~ 32℃) , normal temperature(36 ℃ ~ 37 ℃ ) and hyperthermia(39℃~40℃), duration 1 hour by focal homeothermia equipment. The absorbance of VEGF expression in neuron of hippocampus CAl area was detected by immunohistochemistry in 24h, 72h after focal cerebral ischemia, using high definition image analysis. The ultramicrostructure of mitochondrion, endoplasmic reticulum change in hippocampus were observed with electronic microscope 24h, 72h after cerebral ischemia. RESULTS: VEGF expressions increased in neuron of hippocampus CAl area at subhypothermia group and reduce at hyperthermia group, and increase in 24h, reduce in 72h, especially in 31℃ group decreased obviously at 72h. The number of cellular necrosis increased at 24h within neuron of hippocampus CAl area at hyperthermia group and reduce at subhypothermia group, and increase at 72h within neuron of the ipsilateral ischemia hippocampus CAl area at subhypothermia group and reduce at 24h; whereas the number ofcellular necrosis increased at 24h in hyperthermia group and reduce at 72h; in contrast to...