title: Norepinephrine with its precursors and their antagonists haloperidol and phentolamine interact with dye free radicals in opposite ways.
abstract: In the reactions with dye free radicals, catecholamines exhibited reversible electron donor and acceptor properties with the effectiveness increasing from tyrosine to norepinephrine. The physiological antagonists haloperidol and phentolamine showed opposite patterns of behaviour in the same reactions, changing their properties as acceptors to electron donors. The regularity observed is similar to that demonstrated earlier by a variety of Na+ and Ca2+ channel modulators.
mesh_terms: D004396:Coloring Agents; D005609:Free Radicals; D006220:Haloperidol / Q000494:pharmacology*; D006427:Hemin; D007700:Kinetics; D009243:NAD / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010646:Phentolamine / Q000494:pharmacology*; D010777:Photochemistry
chemical_list: D004396:Coloring Agents; D005609:Free Radicals; D009243:NAD; D006427:Hemin; D006220:Haloperidol; D009638:Norepinephrine; D010646:Phentolamine