Influence Of Hyperglycemia On The Expression Of Glucose Transporter -1 In Microvessels Of Rat Brain Following Cerebral Ischemia

Objective: To investigate the expression of glucose transporter 1 in cerebral microvessels of normal rats and rats with hyperglycemia following focal ischemia.,and to explore the influence of hyperglycemia on GLUTl expression.Methods : We used streptozotocin(STZ) to induce chronic diabetic experimental models and we made focal permanent cerebral ischemia models by occluding the middle cerebral artery with nylon line in rats.The changes of GLUTl expression in brain tissues were investigated by immunohistochemistry.Results : It was found that the expression of GLUTl in cerebral microvessels started to increase at 3h following cerebral ischemia,then gradually increased, peaked at 24h,decreased at 3d.There was no significant difference at 7d compared with sham operation group.GLUTl labeled microvessels were mainly found in the periphery of the ischemia area at every timepoint.We also found that GLUTl labeled microvessels were also detected in the contralateral hemisphere,but it was much lower than the ischemic side.According to diabetic rats,the expression of GLUTl in cerebral microvessels started to increase at 3h after crebral ischemia,peaked at 12h,decreased at 2d. There was no significant difference at 3d and 7d compared to sham operation group.It was much lower than that of normal rat at every timepoint except at 7d.Conclusions: The expression of GLUTl in cerebral microvessels is upregulated following cerebral ischemia.Hyperglycemia has the effect that it can reduce the upregulation compared with normal blood glucose.