AIM: To measure the expression of stromal cell derived factor-1(SDF-1)and vascular endothelial growth factor(VEGF)in retina of diabetic rats model at the different stage and explore the inhibitory effect of AMD3100 on the expression of SDF-1 and VEGF mRNA by RT-PCR and Western-Blot test.

METHODS: RT-PCR and Western-Blot tests were carried out. In RT-PCR test, 60 adult SD rats were divided into normal group, antagonist group, and diabetes group. After diabetic rat model was induced using streptozotocin and antagonist group and diabetic group were injected intravitreously and postocularly with AMD3100 and PBS respectively. All rats were killed and the retina was extracted. after 1,3,5 months and the HE stain of paraffin sections was used and the expression of SDF-1 and VEGF mRNA were measured with RT-PCR. In Western-Blot test, 18 rats were divided into normal group, diabetes group and four antagonist groups which were using different concentration of AMD3100, and killed after 3 months.

RESULTS: SDF-1 and VEGF mRNA were expressed in normal group, antagonist group and diabetes group. At the same age group(1, 3 and 5 months)and among the normal group, antagonist group and diabetes group, the difference of expression of SDF-1 and VEGF mRNA were significant. The expressions in diabetic group were always highest and antagonist group lower than diabetic group. The expression of SDF-1 and VEGF mRNA was increased significantly with the extension of disease. The HE Stain of paraffin sections showed DM group had more cell nucleus which protruded internal limited membranes than normal control group and antagonist group. The Western-Blot test showed in 4 antagonist groups the SDF -1 and VEGF protein expression levels gradually decreased with the increases of SDF-1 antagonist AMD3100 concentration, the difference was significant. When intravitreous injected concentration of AMD3100 increased over 10μg/μL, the expression of SDF-1 and VEGF protein did not change, the difference was not statistically significant

CONCLUSION: With the progression of diabetic retinopathy, the expression of VEGF and SDF-1 mRNA in the retinal tissue of diabetic rats increased. The antagonist AMD3100 could reduce the expression of SDF-l, VEGF and inhibit the development of new blood vessels. In a certain concentration range, this inhibitory effect of AMD3100 was dose-dependent.