Role of nicotinamide phosphoribosyltransferase in lipopolysaccharide-induced myocardial injury in rats

Objective To evaluate the role of nicotinamide phosphoribosyltransferase (Nampt in lipopolysaccharide (LPS)-induced myocardial injury in rats.Methods Forty male Sprague-Dawley rats,aged 12 weeks,weighing 210-230 g,were randomly divided into 3 groups (n =10 each) using a random number table:control group (group C),LPS group and FK866 (specific Nampt inhibitor) group (group F).LPS 4 mg/kg was injected intraperitoneally in LPS and F groups,and then FK866 10 mg/kg was injected intraperitoneally in group F.At 6 h after the end of administration,the blood samples were taken from the abdominal aorta for determination of serum concentrations of cardiac troponin Ⅰ (cTnI).Then the animals were sacrificed and myocardial specimens were removed for determination of tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6),and malondialdehyde (MDA) contents,glutathion (GSH)/oxidized glutathione (GSSG) ratio,caspase-3 activity and apoptosis rate.Results Compared with group C,the levels of cTnI,TNF-α,IL-6,MDA and caspase-3 were significantly increased,and GSH/GSSG ratio was decreased in LPS and F groups.Compared with group LPS,the levels of cTnI,TNF-α,IL-6,MDA and caspase-3 were significantly decreased,and GSH/GSSG ratio was increased in group F.There was no significant difference in apoptosis rate among the 3 groups.Conelusion Nampt activation can induce inflammatory responses and oxidative damage and promote cell apoptosis,thus being involved in LPS-induced myocardial injury in rats. Key words: Nicotinamide phosphoribosyltransferase ;  Endotoxemia ;  Myocardium