Korean J Occup Environ Med.  2001 Dec;13(4):385-392.

Autoregulation of Quartz-induced iNOS by iNOS-derived Hydrogen Peroxide in Rat2 Fibroblast

• Kim KA
• Nam HY
• Mun JH
• Jeong JS
• Lim Y
• Chung CK

Abstract

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

Keyword

Quartz; NOS; H2O2; NO; Autoregulation

MeSH Terms

Catalase
Fibroblasts*
Homeostasis*
Hydrogen Peroxide*
Hydrogen*
Nitric Oxide
Quartz
Catalase
Hydrogen
Hydrogen Peroxide
Nitric Oxide
Quartz