Abstract: Objective: To observe the effect of sodium nitroprusside (SNP) or nitro L arginine acid methyl ester (L-NAME) on the NLRP3 inflammasome activation of C2C12 myoblast or differentiated myotubes in inflammatory culture in vitro. Methods: C2C12 myoblasts were stimulated by IFN-γ, then the formation and activation of NLRP3 inflammasome were analyzed by qPCR and Western blot,and the secretion of IL-1β in the cell culture supernatant was detected by ELISA. Further, C2C12 myoblasts induced by IFN-γ were treated by L-NAME or SNP respectively, then the formation and activation of NLRP3 inflammasome and the secretion of IL-1β were analyzed. Results: qPCR and Western blotting detection confirmed that expression of NLRP3, ASC and mature-caspase-1 in C2C12 myoblasts or differentiation myotubes induced by IFN-γ was up-regulated（P<0.01）. ELISA analysis further confirmed that the IL-1β concentration in the medium of C2C12 induced by IFN-γ was up-regulated compared with that of the non stimulating cells（P<0.01）.At 6 h after SNP treatment, a significant down-regulation of mRNA and protein levels of differentiation myotube inflammasome (ASC and NLRP3, caspase-1) was found（P<0.01） and a contrary result was obtained after L-NAME treatment（P<0.05）. Consisvent with the above results, the expression of IL-1βin the culture supernantent was down-regulated or up-regulated by SNP or L-NAME respectively（P<0.05）. Conclusions: In inflammatory conditions, C2C12 myoblasts or differentiation myotubes possess the ability to synthesize inflammasome NLRP3. NO might cause a certain inhibition on the NLRP3 inflammasome formation and activation.

Key words: Nitric Oxide, C2C12 myoblast , Inflammasomes