Enhancement of hydrogen peroxide-induced luminol-dependent chemiluminescence by neopterin depends on the presence of iron chelator complexes.
We have previously shown that neopterin, 6-D-erythro-trihydroxypropyl-pteridine, synthesized by human monocytes/macrophages upon stimulation by interferon-gamma, enhances toxicity of reactive oxygen at neutral or slightly alkaline pH (7.5), but not at acidic pH (below 6.5). In the present study, we explored in more detail the necessary requirements for neopterin to modulate the effects of hydrogen peroxide in a luminol-dependent chemiluminescence assay. We demonstrate that neopterin enhances hydrogen peroxide effects only in the presence of iron chelator complexes like iron-(III)- or iron-(II)-EDTA or iron-(III)-DTPA. Thus, iron chelator complexes together with neopterin may play an important role in macrophage-mediated effector mechanisms.
Murr
C
C
Institute for Medical Chemistry and Biochemistry, University of Innsbruck, Austria.
Fuchs
D
D
Gössler
W
W
Hausen
A
A
Reibnegger
G
G
Werner
E R
ER
Werner-Felmayer
G
G
Esterbauer
H
H
Wachter
H
H
D001708:Biopterins / Q000031:analogs & derivatives* / Q000494:pharmacology; D002712:Chlorides; D004492:Edetic Acid / Q000494:pharmacology; D005290:Ferric Compounds / Q000494:pharmacology; D005296:Ferrous Compounds / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007502:Iron Chelating Agents / Q000494:pharmacology*; D008163:Luminescent Measurements; D008165:Luminol / Q000494:pharmacology*; D008264:Macrophages / Q000502:physiology; D019798:Neopterin; D004369:Pentetic Acid / Q000494:pharmacology
D002712:Chlorides; D005290:Ferric Compounds; D005296:Ferrous Compounds; D007502:Iron Chelating Agents; D001708:Biopterins; C020748:ferrous sulfate; D008165:Luminol; D019798:Neopterin; D004369:Pentetic Acid; D004492:Edetic Acid; D006861:Hydrogen Peroxide; C024555:ferric chloride