Document Type : Original Article


Physiology Research Center, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran


Background: Diabetic neuropathy (DN) is known as the most troublesome of diabetes mellitus complications. There is a cross-talk between Cyclooxygenase-2 (COX-2) and enzyme NO synthase (NOS) in pain pathophysiology in dorsal root ganglion and the spinal cord. The drive of this study was to calculate the possible role of NOS inhibitor, N(ω)-nitro-L-arginine methyl ester (L-NAME), or inhibitor of COX-2, celecoxib, alone and also the interaction between celecoxib and NOS on hyperalgesia and allodynia in rats with DN. Methods: Streptozotocin (STZ)(60 mg/kg, i.p Once) used to induce diabetes in the male wistar rats. After 72 hours, animals divided to groups which received celecoxib (5 mg/kg), L-arginine (L-ARG) (50 mg/kg) or L-NAME (50 mg/kg) alone or combination of celecoxib with L-ARG or L-NAME. Von-fery test and acetone test were used for evaluation of hyperalgesia and allodynia 14 days after treatment. Results: A significant increase in withdrawal threshold level was observed in the groups receiving celecoxib alone (p<0.001) or in combination with L-ARG (p<0.001) or L-NAME (p<0.001). Percentage of reaction in Acetone test in groups celecoxib, L-NAME, celecoxib+L-ARG and celecoxib+L-NAME were decreased significantly (p<0.001) compared with diabetic control. Conclusion: The main finding was that inhibition of the COX-2 and NOS reduced hyperalgesia and mechanical allodynia in the diabetic rats. Also, the results revealed that there is cross-talk between these two enzymes .


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