Interaction of nitrergic system and Cyclooxygenase-2 on serum level of leptin in diabetic neuropathy in male rats

Diabetic neuropathy is a chronic disease characterized by allodynia and hyperalgesia. Many different studies show that nitric oxide, prostaglandin E2, preinflammatory cytokines and adipocytokines such as leptin increase in diabetic neuropathy. The purpose of this study was to investigate the effect of Cyclooxygenase-2 enzyme and nitrergic system on serum level of leptin in diabetic neuropathy.

Diabetes was induced in rats by streptozotocin (60 mg/kg, i.p). Separate groups of rats were treated with celecoxib (5 mg/kg), L-arginine (50 mg/kg), L-NAME (50 mg/kg), combination of celecoxib and L-arginine, and combination of celecoxib and L-NAME. Serum level of leptin was measured 14 days after streptozotocin injection.

The leptin level significant decreased in all experimental groups (p < 0.01) except for L-arginine group which showed an increase in the leptin level.

Inhibition of cyclooxygenase 2 can reduce the serum level of leptin in diabetic neuropathy. Nitrergic system is partly responsible for this effect.