Prove Into The Acute Global Cerebral Ischemia-reperfusion Injury And The Possible Mechanisms In The Moderate Bilateral Common Carotid Stenosis In The Rabbits

Objective To observe the effects of moderate bilateral common carotid stenosis against the acute global cerebral ischemic-reperfusion injury and detect the expressions of VEGF, Beclinl, RAM-11 in the rabbits.Methods 80 male New Zealand white rabbits were randomly divided into normal group (A, n=5), stenotic sham-operated group (B, n=5), stenotic group (C, n=5), stenotic+ischemia sham-operated group (D, n=5), ischemia-reperfusion model group (E, n=30), stenotic +ischemia-reperfusion model group (F, n=30), fifteen minutes bilateral hemispheric ischemia, the reperfusion was performed at 1,3,6,12,24, 96h of group E and F. " Suture needle control method" can establish the moderate bilateral carotid artery stenosis, establish acute global cerebral ischemia reperfusion model after carotid artery stenotic of group C, D, F and sham stenotic operation of group B of 15 days. The method "occlusion of bilateral carotid artery and vertebral artery+steady the blood pressure" can establish the acute global cerebral ischemia-reperfusion injury model. Get the right frontal parietal cortex according to the corresponding time. The changes of structure and the number of Nissl body can be observed under the HE and Nissl body staining.The expression of Beclinl, VEGF and RAM-11 were then determined by immunohistochemistry assay. The formation of autophagosome and the activation of lysosome were observed in neuron after acute bilateral hemispheric ischemia-reperfusion injury by using transmission electron microscope (TEM).The neuronal apoptosis in ischemia-reperfusion rabbit brains were evaluated by TUNEL assay.Results 1. There were no obvious significance of structure between group A, B, C and D, there existed different extent of ischemia-reperfusion injury of group E and F. The number of Nissl bodies have no obvious differences between group A, B, C and D (P>0.05), the number of Nissl bodies of group E and F reduced of different degrees, the number of Nissl bodies in group F were more than in group E at the corresponding time (P<0.05).2. The results of immunohistochemistry examines showed that:(1)The expressions of Beclin1 in group A, B, C and D were low, and there were no significant differences among the four groups (P>0.05), the expressions of Beclin1 in group E and F increased from 1h (P<0.05), and rose to the climax at 6h, still maintained a high level of expression at 96h. The expressions of Beclin1 in group F were higher than in group E at the corresponding time (P< 0.05). (2) The expressions of VEGF in group A and B showed the low levels, the expressions of VEGF in group C and D were higher than in group A or B, the expressions of VEGF in group E or F increased from 1h (P<0.05), and rose to the climax at 24h, the expressions of group E and F still maintained a high level of expression to 96h, the expressions in group F were higher than in group E at the corresponding time (P< 0.05). (3) The expressions of RAM-11 in group A,B,C and D showed the low levels, and there were no significant differences among the groups (P>0.05), the expressions of RAM-11 in group E, F rose to the climax at 12h, still maintained a high level of expression to 96h, the expressions in group E were higher than in group F at the corresponding time (P<0.05).3. There were a few of autophagosomes and lysosomes in neuron of group A, B, C and D, the formation of autophagosomes and enhanced presence of lysosomes could been seen at 1h, and its number were significantly increased at 3h, and still could be found at 96h. 4. There were few apoptotic cells in group A, B, C and D, group E and F had no obvious significance in 3h(P>0.05), but the number of group E and F had obviously increased in 6h (P<0.01) and came to a climax at 12h and then fell slowly. The number of apoptotic cells in group F were less than in group D at the corresponding time (P<0.05).Conclusions 1.The acute global cerebral ischemic-reperfusion injury was reduced by moderate bilateral common carotid stenosis in rabbits.2. VEGF and RAM-11 may participate in the neuroprotection of ischemia-reperfusion injury after the moderate bilateral common carotid arteries stenosis, autophagy may play an important role in the neuroprotection in the early term after ischemia-reperfusion.