Nitric oxide (NO) has been proposed to play a role in a variety of inflamma
tory diseases. Sodium salicylate (NaSal) is the most commonly used anti-inf
lammatory agent. We investigated whether NaSal can diminish the production
of NO in TM4 Sertoli cells. TM4 Sertoli cells produced a small amount of NO
upon treatment with recombinant interferon-gamma (rIFN-gamma). The effect
of rIFN-gamma was enhanced markedly by the addition of recombinant TNF-alph
a (rTNF-alpha) in a dose-dependent manner. NaSal (10 and 20 mM) significant
ly inhibited NO production from TM4 Sertoli cells induced by rIFN-gamma plu
s rTNF-alpha. Tn addition, rIFN-gamma in combination with rTNF-alpha showed
a marked increase of the expression of inducible NO synthase (iNOS) protei
n. Western blot analysis revealed that NaSal (10 and 20 mM) blocked a step
of iNOS protein synthesis. The rIFN-gamma plus rTNF-alpha-induced nuclear f
actor kappa B (NF-kappa B) activation was significantly blocked by NaSal (1
0 and 20 mM). On the other hand, neither staurosporine nor polymyxin B sign
ificantly inhibited NO production from TM4 Sertoli cells induced by rIFN-ga
mma plus rTNF-alpha. The present results indicate that NaSal inhibits rIFN-
gamma plus rTNF-alpha-induced NO production in TM4 Sertoli cells via the si
gnal transduction pathway of NF-kappa B activation. (C) 2000 International
Society for Immunopharmacology. Published by Elsevier Science Ltd. All righ
ts reserved.