Influence of nitric oxide on luminol-enhanced chemiluminescence measured from porcine-stimulated leukocytes.
The influence of endogenous nitric oxide (NO) and NO-releasing compounds on free radical release from porcine leukocytes was investigated by luminol-enhanced chemiluminescence (CL). The direct free radical-scavenging activity of the compounds was determined by a cell-free system using xanthine plus xanthine oxidase (X + XO). The NO donor, N-(2-hydroxyethyl)nicotinumide nitrate (nicorandil), markedly inhibited CL generated by phorbol myristate acetate (PMA)-stimulated leukocytes. In addition, nicorandil and S-nitrozo-N-acetylpenicillamine (SNAP) both decreased CL generated by X + XO. Conversely, C87 3754, a NO-releasing sydnonimine, decreased free radical release from leukocytes only when preincubated with the cells and had no effects on the X + XO system. None of the NO donors inhibited peroxynitrite-generated CL. L-, but not D-, arginine inhibited PMA-activated free radical generation without affecting X + XO-induced CL. L-Canavanine, N omega-nitro-L-arginine (L-NNA), and L-nitro-arginine methyl ester (L-NAME), inhibitors of the NO pathway, augmented PMA-induced CL. However, L-canavanine, but not L-NNA and L-NAME, produced a significant inhibition of X + XO-induced CL. It is concluded that endogenous NO may play an important role in the measurement of free radicals released from porcine leukocytes, assessed by luminol-enhanced CL, and that compounds with NO-releasing properties decrease CL, possibly by interfering with free radical generation.
Demiryürek
A T
AT
Department of Physiology & Pharmacology, University of Strathclyde, Glasgow, Scotland.
Kennedy
S
S
Wainwright
C L
CL
Wadsworth
R M
RM
Kane
K A
KA
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives*; D002474:Cell-Free System; D007202:Indicators and Reagents / Q000494:pharmacology; D007962:Leukocytes / Q000187:drug effects* / Q000378:metabolism; D008163:Luminescent Measurements; D008165:Luminol / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009536:Niacinamide / Q000031:analogs & derivatives / Q000494:pharmacology; D020108:Nicorandil; D009569:Nitric Oxide / Q000378:metabolism*; D013552:Swine; D013558:Sydnones / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology*; D019820:Xanthine; D014969:Xanthine Oxidase / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
D007202:Indicators and Reagents; D013558:Sydnones; D014665:Vasodilator Agents; D014970:Xanthines; C072857:3-(cis-2,6-dimethylpiperidino)sydnonimine; D019820:Xanthine; D009536:Niacinamide; D020108:Nicorandil; D009569:Nitric Oxide; D008165:Luminol; D001120:Arginine; D014969:Xanthine Oxidase; D013755:Tetradecanoylphorbol Acetate; D019331:NG-Nitroarginine Methyl Ester