Nitric oxide production by human peripheral blood mononuclear cells.

Journal article

INTRODUCTION: There are conflicting data on the ability of human mononuclear cells to produce nitric oxide (NO). We investigated nitric oxide production from peripheral blood mononuclear cells (PBMs) by using a new sensitive fluorescent indicator. MATERIALS AND METHODS: PBMs from healthy volunteers were collected, plated in 96-well microplates, and loaded with the fluorescent nitric oxide probe, 4,5-diaminofluorescein diacetate (DAF-2DA). Experiments were performed in normal control and endotoxin-stimulated PBMs, with and without exogenous L-arginine. The exogenous nitric oxide donor S-nitroso-N-acetyl-penicillamine (SNAP) was used as a positive control. Fluorescence intensity was measured with a fluorescence microplate reader. RESULTS: Nitric oxide production by human PBMs can be demonstrated by the use of the fluorescent indicator, DAF-2DA, in both control and endotoxin-stimulated conditions. Nitric oxide production was independent of the concentration of exogenous L-arginine. The addition of endotoxin did not change nitric oxide production. PBMs treated with SNAP showed a concentration dependent increase in fluorescence. Nitric oxide production over 5 hours was constant and identical in both control and stimulated groups. CONCLUSION: This fluorescent indicator technique is useful for the study of NO production by human PBMs. Nitric oxide production by PBMs was independent of exogenous L-arginine concentration and was not affected by endotoxin.

Authors: Toomtong, P; Young, J

• Publication status: Published
• Journal: Annals of the Academy of Medicine, Singapore
• Volume: 30
• Issue: 3
• Pages: 270-273
• Publication date: 2001-05-01
• ISSN: 0304-4602
• Language: English
• Keywords: Reference Values; Nitric Oxide Donors; Lipopolysaccharides; Humans; Leukocytes, Mononuclear; Fluorescent Dyes; Fluorescein; Penicillamine; Indicators and Reagents; Nitric Oxide; Escherichia coli; Arginine; Endotoxins