Abstract: Objective To investigate the influence of propylene glycol mannate sulfate(PGMS)on the expression of vascular endothelial growth factor(VEGF)in diabetic retinopathy(DR)by a rat model, to study the mechanism of PGMS againstDR, and to provide a reliable theoretical and experimental evidence for the PGMs to be applied to clinical prevention and treatment of DR. Methods Male Wistar rats were randomized into the normal control group, the diabetic control group and the PGMS group. The PGMS group was subdivided into the low-dose PGMS group and high-dose PGMS group, with doses of 50 mg/kg and 100 mg/kg, respectively. The 1% Streptozotocin(STZ)of 60 mg/kg was intraperitoneally injected in rats to establish the diabetic models. The PGMS with the doses of 50 mg/kg and 100 mg/kg were used to gavage in different groups of models for 12 weeks. Twelve weeks later, the animals were sacrificed and retinas were isolated. The aqueous humor and serum were taken, expressions of VEGF protein in retina, aqueous humor and serum were detected by ELISA, respectively. The location and the expression of VEGF protein in 山东大学耳鼻喉眼学报31卷2期 -周玮琰,等.甘糖酯对糖尿病大鼠视网膜病变中血管生成因子VEGF表达的影响 \=-retina tissue was detected by immune-histochemistry. Real-time RT-PCR was used to measure the expression of VEGF mRNA in retinas. Results Twelve weeks after the use of PGMS,the level of blood glucose was not changed. ELISA showed that the expression of VEGF protein in serum was not significantly changed in different groups(P>0.05), but the expression of VEGF protein in aqueous humor and retina was significantly increased in diabetic control group than normal control group(P<0.05), but the groups which PGMS was given reduced, lower than that DM group, showing statistically significant differences(P<0.05). Immunohistochemistry showed that the VEGF protein was almost not expressed in normal control group, but the VEGF protein was highly expressed in diabetic control group. The expression mainly located in the ganglion cell layer, the inner plexiform layer, outer nuclear layer. The VEGF protein was weakly expressed at the group of PGMS. Real-time RT-PCR showed the expression of VEGF mRNA was lower in normal control group. The expression of VEGF mRNA in diabetic control group was almost 2.12 times than normal control group. The expression was decreased obviously in the group of PGMS. Conclusion PGMs has a good control effect on early diabetic retinopathy. PGMS can treat the diabetic retinopathy by downregulating the expressions of VEGF in early diabetic retinopathy.

Key words: Diabetic retinopathy, Vascular endothelial growth factor, Propylene glycol mannate sulfate