TY - JOUR
T1 - Endogenous nitric oxide production by human monocytic cells regulates LPS-induced TNF production
AU - Zinetti, M.
AU - Fantuzzi, G.
AU - Delgado, R.
AU - Di Santo, E.
AU - Ghezzi, P.
AU - Fratelli, M.
PY - 1995
Y1 - 1995
N2 - The ability to produce nitric oxide (NO) of human monocytes macrophages is object of debate. While studying the regulation of tumor necrosis factor (TNF) synthesis induced by endotoxin (LPS) in a human cell line of monocyte origin (THP-1) and in human peripheral blood mononuclear cells (PBMC) we found an indirect evidence of such production. We showed that L-N-monomethyl-arginine (L-NMMA), an inhibitor of NO synthase, and hemoglobin, a chelator of NO, are able to significantly reduce TNF synthesis, indicating that NO production is induced by LPS and contributes to the induction of TNF. Since NO is a known cytostatic agent, we also studied the cytostatic effect of LPS, and demonstrated that it is reverted by L-NMMA. Although we were unable to show any nitrites/nitrates accumulation in the culture media, taken together our data give an indirect evidence of a physiologically relevant LPS-induced NO production in human monocytes-macrophages.
AB - The ability to produce nitric oxide (NO) of human monocytes macrophages is object of debate. While studying the regulation of tumor necrosis factor (TNF) synthesis induced by endotoxin (LPS) in a human cell line of monocyte origin (THP-1) and in human peripheral blood mononuclear cells (PBMC) we found an indirect evidence of such production. We showed that L-N-monomethyl-arginine (L-NMMA), an inhibitor of NO synthase, and hemoglobin, a chelator of NO, are able to significantly reduce TNF synthesis, indicating that NO production is induced by LPS and contributes to the induction of TNF. Since NO is a known cytostatic agent, we also studied the cytostatic effect of LPS, and demonstrated that it is reverted by L-NMMA. Although we were unable to show any nitrites/nitrates accumulation in the culture media, taken together our data give an indirect evidence of a physiologically relevant LPS-induced NO production in human monocytes-macrophages.
KW - Human monocytes/macrophages
KW - Nitric oxide
KW - Tumor necrosis factor
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M3 - Article
C2 - 7795174
AN - SCOPUS:0029025297
VL - 6
SP - 45
EP - 48
JO - Environmental and Molecular Mutagenesis
JF - Environmental and Molecular Mutagenesis
SN - 0893-6692
IS - 1
ER -