Objective: To investigate the effect of dexamethasone (DEX) on the microglia activation induced by glutamic acid (GLU) in rats.
Methods: We isolated and cultured the microglia from the spinal cord of SD infant rats in vitro. The cell purity was tested by immunofluorescence technique. The cells were then randomly divided into 5 groups: Dulbecco' s phosphate buffered saline treatment (DPBS group); GLU treatment (GLU group); DEX pretreatment and then GLU stimulation; simultaneous treatment of DEX and GLU; GLU stimulation followed by DEX treatment. Finally, immunofluorescence technique was used to investigate the expressions of glucocorticoid receptor (GR) and CD11b/c protein.
Results: Compared with the DPBS group, GLU group presented the increased expression of CD11b/c protein, the shorten length of cell processes as well as cell shape turning round. Furthermore, compared with the GLU group, the CD11b/c protein expression significantly decreased in the group treated simultaneously with DEX and GLU and the group treated with DEX after GLU stimulation. However, the expression was not different between the GLU group and the group treated with DEX and then stimulated by GLU.
Conclusion: DEX could inhibit microglia activation induced by GLU, while DEX pretreatment have no such an effect on microglia.