Objective:To investigate the effects of high glucose on rat brain microvascular endothelial cells(BMEC).Methods: Brain microvascular endothelial cells(BMEC)of Wistar rat cerebral cortex were cultured in 5.05mmol/L glucose

15 and 30mmol/L glucose media respectively for 24h

and then BMEC activity or injury was assayed by observing cell ultramicrostructures morphology and adopting methyl thiazolyl tetrazolium(MTT)assay.The ET-1 concentrations were evaluated by radioimmunoassay.Situ hybridization used to detect the ET-1 mRNA expression.Results:The BMEC activity and viability assessed by MTT were decreased when glucose concentrations rose.The ultrastructure of BMEC was damaged and the content of ET-1 in BMEC media was increased.Furthermore

ET-1 mRNA expression was not induced by high concentration of glucose.Conclusions:High concentration of glucose has a significant effect of BMEC injury.The data suggest that ET-1 may play important role in the early state of diabetic microvascular complications.