Inhibition of monocyte luminol-dependent chemiluminescence by tetrahydrobiopterin, and the free radical oxidation of tetrahydrobiopterin, dihydrobiopterin and dihydroneopterin.
Luminol-dependent chemiluminescence of normal human monocytes activated by zymosan is demonstrated to be inhibited by tetrahydrobiopterin in a concentration-dependent manner. The reduced pterins tetrahydrobiopterin, dihydrobiopterin, and dihydroneopterin are all shown to be readily oxidized by the hydroxyl radical. The susceptibility of reduced pterins to free radical attack may explain the inhibition of chemiluminescence observed and an additional role of reduced pterins as free radical scavengers in tissues is considered.
Heales
S J
SJ
Department of Molecular Sciences, University of Aston, Birmingham, U.K.
Blair
J A
JA
Meinschad
C
C
Ziegler
I
I
D001205:Ascorbic Acid / Q000494:pharmacology; D001708:Biopterins / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology; D004226:Dithioerythritol / Q000494:pharmacology; D005609:Free Radicals; D006801:Humans; D006861:Hydrogen Peroxide; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D019798:Neopterin / Q000031:analogs & derivatives; D010084:Oxidation-Reduction; D011621:Pteridines / Q000097:blood
D005609:Free Radicals; D011621:Pteridines; C000976:7,8-dihydroneopterin; D001708:Biopterins; D019798:Neopterin; C017226:7,8-dihydrobiopterin; D004226:Dithioerythritol; D006861:Hydrogen Peroxide; C003402:sapropterin; D001205:Ascorbic Acid