Purpose:.To detect the expression of Netrin-1 in the retinas of diabetic rats and evaluate the relationship between Netrin-1mRNA and diabetic retinopathy(DR).Methods:.Twenty healthy adult male Sprague-Dawley(SD)rats were randomly divided into a diabetic model group(DM)and a normal control group(NC), each group was composed of ten rats..Sreptozocin(STZ)was administered intraperitoneally at a single dose of 60 mg / kg to diabetic group. The control rats were injected only with citrate buffer. Collection of serum at 72 h after STZ treatment and measuring blood glucose levels confirmed the development of diabetes..The rats with blood glucose level 16.67 mmol / L or higher were considered to be diabetic and were used in the experiment. Retinal tissues were harvested and expression of netrin-1 mRNA and protein in the retina tissues was examined by reverse transcription polymerase chain reaction(RT-PCR) and western blot analysis, respectively.Results:.Diabetic rats showed classic symptoms of diabetes mellitus,.such as polydipsia,.polyphagia,.and polyuria.Cataract was seen in the DM group at 3 months after administration of STZ. Both netrin-1 mRNA and protein levels retina were dramatically increased in the DM rats compared to the NC group(P<0.05).Conclusion:Diabetic rats can be successfully established by intraperitoneal injection of streptozotocin(60 mg / kg). Netrin-1 may play an important role during the development of diabetic retinopathy. Objective: .To detect the expression of Netrin-1 in the retinas of diabetic rats and evaluate the relationship between Netrin-1 mRNA and diabetic retinopathy (DR). Methods:. Twenty healthy adult male Sprague-Dawley a diabetic model group (DM) and a normal control group (NC), each group was composed of ten rats..Sreptozocin (STZ) was administered intraperitoneally at a single dose of 60 mg / kg to diabetic group. only with citrate buffer. Collection of serum at 72 h after STZ treatment and measuring blood glucose levels confirmed the development of diabetes. The rats with blood glucose level 16.67 mmol / L or higher were considered to be diabetic and were used in the experiment. Retinal tissues were harvested and expression of netrin-1 mRNA and protein in the retina tissues was examined by reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis, respectively. Results:. Diabetic rats showed typical symptoms of diabetes mellitus, .such as polydipsia, .polyphagia,. and polyuria. Cataract was seen in the DM group at 3 months after administration of STZ. Both netrin-1 mRNA and protein levels retina were dramatically increased in the DM rats compared to the NC (P <0.05) .Conclusion: Diabetic rats can be successfully established by intraperitoneal injection of streptozotocin (60 mg / kg). Netrin-1 may play an important role during the development of diabetic retinopathy.