cnIntravitreal glutamate injection induces an increased phosphorylation of ERK1/2 in retinal M¨¹ller cells of rats

    ZHOU Runª²Hai1,YAN Hong1,Duan Xiaoª²Li2,WANG Baiª²Ren2

    1Department of Ophthalmology, Tangdu Hospital, Xi¬ðan 710038,China, 2PLA Institute of Neurosciences , School of Basic Medicine,Fourth Military Medical University , Xi¬ðan 710033 , China

    ¡¾Abstract¡¿ AIM: To analyze the changes of phosphoª²ERK1/2 in retinal M¨¹ller cells by using an intravitreal glutamate insult and to explore the neuroprotection role of activated (phosphorylated) ERK1/2 against glutamate cytotoxicity in retina. METHODS: A 2 ¦ÌL of saline or glutamate (375 nmol) was injected into the random unilateral vitreous body for 3 d or 7 d in 18 SD rats. The rats were randomly divided into 3 groups: Control group (saline injections), glutamate injections 3 d group and glutamate injections 7 d group. The changes of the activated ERK1/2 were studied by immunohistochemical staining and computerª²picture analytic system. RESULTS: After 7 d intravitreal glutamate insult, the activated phenotypes of retinal cells exhibited a hypertropic morphology and increased immunostaining for ERK1/2. By the staining pattern in shape and localization, the positive cells were presumed to be M¨¹ller cells. The gray level of glutamate injections 7 d group was the lowest among the 3 groups. The difference between glutamate injections 7 d group and other two groups was significant (P<0ª±05). CONCLUSION: Increased phosphorylated ERK1/2 in retinal M¨¹ller cells by using an intravitreal glutamate insult suggests that phosphoª²ERK1/2 plays an important neuroprotective role when retinal ganglion cells are injured by glutamate cytotoxity. ......