Expression of PDGF-B in retina of rats with early-stage diabetic retinopathy

AIM: To observe the expression of platelet-derived growth factor-B chain(PDGF-B) mRNA in the retina of diabetic rats at the early stage of diabetic retinopathy.METHODS: A total of 60 healthy adult male Wistar rats were randomly divided into control and diabetic groups.Streptozotocin(60 mg/kg) was injected into the tail vein to induce diabetes in 35 rats in diabetic group,while 25 rats in control group were treated with the same volume of citric acid buffer solution.On the 3rd day after injection,the rats whose urine glucose was more than ++ and fasting blood glucose ≥16.7 mmol/L were chosen as laboratory objects.At the end of 1st,2nd and 3rd months,6 rats in both groups were randomly sacrificed and the retinas were dissected and total RNA was isolated for the detection of mRNA for PDGF-B by semi-quantitative reverse-transcription polymerase chain reaction(RT-PCR).The retinas of the other rats in both groups were taken and prepared as the ultrathin and observed by transmission electron microscope.RESULTS: The levels of mRNA encoding PDGF-B in the retinas of diabetic rats were significantly higher than those in controls at each observed time point(P0.05 or P0.01 at the end of 1st and 3rd month).Obvious ultrastructural damages,which were in relation to the course of diabetes,could be seen in the retinas of diabetic rats.CONCLUSION: Diabetes upregulates PDGF-B mRNA levels in the retinas of diabetic rats in a time-dependent manner.