Objective 　To observe the effect of pigment epithelium-derived factor (PEDF）on glutamate metabolism in diabetic rat retina. Methods 　78 Sprague-Dawley rats were randomly divided into the model group, model control group, PEDF intervention group and intervention control group. There were some dead and euglycemia rats at the end of experiment, so only 12 rats in each group were included in the statistical analysis. The diabetic retinopathy rat model of the model, PEDF intervention and intervention control group were induced with streptozotocin injection. The rats in the model group were not intervened. The monthly-age matched normal rats of model group were in the model control group. The left eyes of rats were received intravitreal injection with 5  mu;l (0.1  mu;g/ mu;l) PEDF (PEDF intervention group) or 5  mu;l phosphate buffer solution (intervention control group). The expressions of L-glutamate/L-aspartate transporter in retina were analyzed by western blot and real time RT-PCR techniques and glutamate content in retina was analyzed by high-pressure liquid chromatography (HPLC). Cultured rat M uuml;ller cells were divided into the control,experimental, PEDF intervention and intervention control group, GLAST expressions were detected by fluorescence immunofluorescence and real-time RT-PCR techniques. The glutamate up-take activity of M uuml;ller cells was determined by intracellular [3H] labeled D, L-glutamate concentration with scintillation counting. Results 　Western blot and real-time RT-PCR showed that GLAST expression decreased (real-time RT-PCR：t=8.86,P lt;0.01；Western blot：t=3.42,P＜0.05), glutamate content increased（t=4.01,P＜0.05）in model group compared with the model control group; GLAST expression increased (real-time RT-PCR：t=3.56,P＜0.05；Western blot：t=3.52,P＜0.05), glutamate content decreased（t=4.36,P＜0.05）in the PEDF intervention group compared with the intervention control group. Real-time RT-PCR and fluorescence immunofluorescence showed that high glucose down-regulate GLAST expressions in M uuml;ller cells (rea-time RT-PCR：t=3.48,P＜0.05；fluorescence immunofluorescence：t=4.72,P＜0.05 ) and impair glutamate uptake activity of M uuml;ller cells (t=3.81, P lt;0.05). Under high glucose conditions, PEDF up-regulated GLAST expression significantly (real-time RT-PCR：t=6.82,P＜0.01；fluorescence immunofluorescence：t=3.72,P＜0.05) and ameliorated the glutamate up-take activity of M uuml;ller cells（t=4.14, P lt;0.05). Conclusions 　In diabetic rats, PEDF may improve the activity of GLAST in M uuml;ller cells, thus ameliorate retinal glutamate metabolism and inhibit death of retinal ganglion cells.

Citation： 沈玺,焦秦,钟一声,谢冰. The effect of pigment epithelium-derived factor on glutamate metabolism in diabetic rat retina. Chinese Journal of Ocular Fundus Diseases, 2011, 27(3): 226-230. doi: Copy