Expression of Netrin-1 in diabetic rat retina.

PURPOSE: 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 (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.