ABSTRACT
Background and Aim: Nicotinamide phosphoribosyltransferase [NAMPT]/ [visfatin] have been proposed as proinflammatory cytokine that is influenced by blood glucose or insulin. In diabetes mellitus proinflammatory agents such as prostaglandin E2 and nitric oxide can increase visfatin synthesis and visfatin stimulates their expression. The aim of this study was to determine the effect of cyclooxygenase and nitrergic system on serum visfatin level and some biochemical parameters in diabetic rats
Material and Methods: Male Wistar rats were rendered diabetic by streptozotocin [60 mg/kg, i.p.]. Animals were treated with celecoxib [5 mg/kg] or L-arginine [50 mg/kg] or L-NAME [50 mg/kg] alone or with combinations of celecoxib and L-arginine or celecoxib and L-NAME. Using SPSS software, we used one way analysis of variance followed by tukey test for data analysis
Results: All treated groups showed significant decrease in blood glucose and triglyceride levels [P<0.05]. Treatment with L-NAME decreased serum insulin level significantly [P<0.05], while celecoxib alone [P<0.05] or in combination with L-NAME and L-arginine enhanced its levels significantly [P<0.01]. Serum visfatin level increased in diabetic rats compared to controls [P<0.05]. Treatment with L-arginine had a significant effect on increasing visfatin level [P<0.05]. Celecoxib decreased visfatin level [P<0.01]. Combination of L-NAME or L-arginine with celecoxib caused a greater reduction in visfatin level [P<0.01]
Conclusion: Serum visfatin level increased in streptozotocin- induced diabetes. Inhibition of cyclooxygenase-2 by celecoxib, resulted in decreased visfatin level and part of this effect was due to interaction with nitrergic system. It seems that blood glucose and insulin do not affect visfatin level directly, but proinflammatory cytokines play the main role in its synthesis