The Expression And The Intervention Of Aquaporin-4 In Sprague-Dawley Rat Astrocytes Cultuled By The Ammonia And Glutamate

Objective To investigate the relationship between aquaporin-4(AQP4) and hepatic encephalopathy and to explore the effect of the U0126,a MAPKs signal transduction pathway inhibitor,dexamethasone and dimethyl sulfoxide on the expression of AQP4 in Sprague-Dawley rat astrocytes cultured by the ammonia and glutamate in vitro,providing the theory basis for further research on new medicines to treat hepatic encephalopathy and brain edema.Methods Brain astrocytes in Sprague-Dawley rat were isolated and cultured,and then the morphology and ultra microstructure of cells were observed by inverted phase contrast microscope and transmission electron microscope.Calcium fluorescent indictor of Flluo-3/Am was used to detect the variations of calcium in astrocytes.Automatic chemistry analyzer was used to detect the LDH.The expressional change of AQP4 protein and mRNA was determined by the immunohistochemistry(IHC) and reverse transcription -ploymerase chain reaction.The change of above-mentioned subjects were observed by U0126,dexamethasone and dimethyl sulfoxide.Results Ammonia and glutamate could induce astrocytes death,increasing the level of intracellular free calcium, leading to LDH releasing and increasing the expression of AQP-4 mRNA and protein. U0126,dexamethasone and dimethyl sulfoxide could decrease astrocytes death induced by ammonia and glutamate,reducing cell LDH leakage and decreasing the concentration of calcium.The expression of AQP-4 mRNA and protein could be inhibited with U0126,dexamethasone and dimethyl sulfoxide. Conclusion Ammonia and glutamate can increase the expression of AQP-4,the expression of AQP-4 increasing as long as the increasing of the ammonia.U0126,dexamethasone and dimethyl sulfoxide can decrease the expression of AQP-4,and effectively protect the brain astrocytes.