RESUMO
Objective To observe the effects of Hedysari Polysaccharide (HPS) on the expressions of TSP-1 and PDGF-B in the retina of diabetic rats;To discuss the protective effect and possible mechanism on diabetic retinopathy. Methods The diabetic model was established by intraperitoneal injection of streptozotocin. 50 male SPF Wistar rats were randomly divided into 5 groups:model group, calcium dobesilate group, and HPS high-, medium-, and low-dose group, extra 10 rats were set as the normal group, 10 rats in each group. Each administration group was given relevant medicine for gavage, while model group and normal control group were given same amount NS for gavage, once a day for 8 weeks. The mRNA and protein expression of TSP-1 and PDGF-B were detected by qRT-PCR and immunohistochemistry. The retinal structure was observed by HE staining. Results HE staining showed that each layer of the retina of the model group was clear and complete, but the outer nucleus layer became looser, thinner and more disorderly, and the number of ganglion cells decreased slightly; the administration groups were improved markedly compared with the model group. Compared with the normal control group, the mRNA level and protein expression of retina TSP-1 on the model group dramatically dropped (P<0.01), and those of PDGF-B strikingly increased (P<0.01);Compared with the model group, the mRNA level and protein expression of retina TSP-1 on alladministration groups rose (P<0.05, P<0.01), and those of PDGF-B went down (P<0.01); Compared with all other administration groups, there was statistical significance in the mRNA level and protein expression of retina TSP-1 and PDGF-B on HPS high-dose group (P<0.05, P<0.01). Conclusion HPS may prevent the angiogenesis and proliferation in diabetic retinopathy process through adjusting the content of TSP-1 and PDGF-B in retina of diabetic rats so as to protect the retina.