Expression Of Netrin-1 MRNA In The Retina Of Diabetic Rats

Objective To detect the expression of Netrin-1mRNA in retina of diabetic rats and to evaluate the relationship between Netrin-1mRNA and diabetic retinopathy.Methods 20 adult Sprague-Dawley (SD) rats were randomly divided into two groups, Diabetic model group (DM) and Normal control group (NC),10 rats respectively. Streptozotocin (STZ) in freshly sodium citrate buffer (PH 4.5) was injected into peritoneal cavity in a dose of 60 mg/kg to induce diabetes mellitus. Rats in the control group were injected with the same volumes of sodium Oitrate buffer (approximate 0.5mL). Blood glucose levels higher than 16.67mmol/L were considered to be diabetic rats. Blood glucose and weight were measured every month. The technique of reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of Netrin-1mRNA in retina respectively after STZ injection.Results (1) The success ratio of diabetic rat models was 90%, for one was failed to induce diabetes mellitus. The remained 9 diabetic rats appeared classic symptoms of diabetes mellitus, such as polydipsia, polyphagia, and so on, except the blood glucose. There was significant difference of blood glucose level between DM group and NC group (p< 0.01). There was significant difference of weights increase between two groups. Cataract was seen in the DM group at 3 month after STZ injection. (2) The result of RT-PCR revealed little expression of Netrin-1mRNA in the retina of control group rats. But a considerable increasing expression was seen in DM group (p<0.05).Conclusion Diabetic rat models can be successfully established by a single intraperitoneal injection of streptozotocin (60mg/kg). The expression of Netrin-1 mRNA in the retina of Diabetic rat models are significantly higher than that of the control group.