earticle

영어

Diabetic retinopathy is one of the most important microvascular compli-cations in diabetes, and it is the major cause of visual loss. Physical ex-ercise is known to ameliorate the symptoms of metabolic syndromes such as diabetic mellitus. In the present study, we investigated the ef-fects of treadmill exercise on vascular endothelial growth factor (VEGF) expression and apoptotic cell death in the retinas of streptozotocin (STZ)- induced diabetic rats. The male Sprague- Dawley rats were randomly divided into three groups (n=10 in each group): control group, STZ-in-duce diabetes group, STZ- induced diabetes and treadmill exercise group. To induce diabetes in the experimental animals, a single intra-peritioneal injection of STZ (50 mg/kg) was given to each animal. The rats in the exercise group were forced to run on a motorized treadmill for 30 min once a day during 1 week starting 6 weeks after STZ injec-tion. In the present results, VEGF expression in the retinas was increased by induction of diabetes. The numbers of caspase-3-positive and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)- positive cells in the retinas were also enhanced by induction of diabe-tes. Treadmill exercise significantly decreased VEGF expression and suppressed the number of TUNEL-positive and caspase-3-positive cells in the retinas of diabetic rats. In the present study, we have shown that treadmill exercise might alleviate the progression of diabetic retinopa-thy through suppressing VEGF expression and apoptotic cell death in the retinas of the diabetic rats.