We next determined whether hyperglycemia enhances GDNF-induced apoptosis, proving GDNF-induced apoptosis as significantly increased by hyperglycemia (glucose 5,10,15 and 20 mM vs. control: 5.12±0.75, 5.64±0.68, 6.74±0.82 and 7.82±1.25 vs. 4.95±0.82% p>0.01 in 20 mM glucose; GDNF 100 ng/ml plus glucose 5,10,15 and 20 mM vs. GDNF 100 ng/ml: 12.42±1.47, 14.56±1.65, 17.24±1.84 and 20.85±2.14 vs. 11.25±1.35% p<0.01 in 20 mM glucose. Here, GDNF is linked to Hyperglycemia.