This study was performed in order to investigate the molecular mechanism regulating nitric oxide synthase(NOS) induced by alpha-quartz in Rat2 fibroblast.

alpha-quartz-induced nitric oxide(NO) and H2O2 formation and alpha-quartz-induced iNOS protein expression in Rat2 fibroblast were monitored. With iNOS inhibitor(L-N6-(1-iminoethyl)lysine hydrochloride, L-NIL) or antioxidant(catalase), we observed NO and H2O2 formation and iNOS protein expression in Rat2 fibroblast stimulated with alpha-quartz.

alpha-quartz stimulated iNOS-induced NO and H2O2 formation in Rat2 fibroblast. L-NIL inhibited H2O2 formation and iNOS protein expression by alpha-quartz in Rat2 fibroblast. Pretreatment with catalase blocked the autoinhibitory pathway of iNOS by iNOSinduced H2O2, therefore H2O2 and NO production and iNOS protein expression were increased in Rat2 fibrobalst stimulated with alpha-quartz.

alpha-quartz-induced iNOS stimulated H2O2 formation in Rat2 fibroblast. INOS-induced H2O2 by alpha-quartz plays an important role in the autoinhibition pathway for regulating the iNOS function in Rat2 fibroblast.