title: Superoxide anion radical scavenging property of catecholamines.
abstract: The direct effect of the four catecholamines (adrenaline, noradrenaline, dopamine and isoproterenol) on superoxide anion radicals (O2•) was investigated. The reaction between 18-crown-6-ether and potassium superoxide in dimethylsulfoxide was used as a source of O2•. The reactivity of catecholamines with O2• was examined using chemiluminescence, reduction of nitroblue tetrazolium and electron paramagnetic resonance spin-trapping techniques. 5,5-Dimethyl-1-pyrroline-N-oxide was included as the spin trap. The results showed that the four catecholamines were effective and efficient in inhibiting chemiluminescence accompanying the potassium superoxide/18-crown-6-ether system in a dose-dependent manner over the range 0.05-2 mM in the following order: adrenaline > noradrenaline > dopamine > isoproterenol, with, IC50 = 0.15 ± 0.02 mM 0.21 ± 0.03 mM, 0.27 ± 0.03 mM and 0.50 ± 0.04 mM, respectively. The catecholamines examined also exhibited a strong scavenging effect towards O2• when evaluated this property by the inhibition of nitroblue tetrazolium reduction (56-73% at 1 M concentration). A very similar capacity of O2• scavenging was monitored in the 5,5-dimethyl-1-pyrroline-N-oxide spin-trapping assay. The results suggest that catecholamines tested may involve a direct effect on scavenging O2- radicals.
authors: Department of History of Medicine and Medical Ethics, Pomeranian Medical University, Rybacka 1, 70-204 Szczecin, Poland.
authors: Aleksandra
authors: A
authors: Kładna
authors: Paweł
authors: P
authors: Berczyński
authors: Irena
authors: I
authors: Kruk
authors: Teresa
authors: T
authors: Michalska
authors: Hassan Y
authors: HY
authors: Aboul-Enein
mesh_terms: D000838:Anions / Q000737:chemistry; D002395:Catecholamines / Q000737:chemistry*; D043844:Crown Ethers / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry*; D049449:Luminescence; D015394:Molecular Structure; D013481:Superoxides / Q000737:chemistry*
chemical_list: D000838:Anions; D002395:Catecholamines; D043844:Crown Ethers; D016166:Free Radical Scavengers; D013481:Superoxides; C039316:potassium superoxide; C015762:18-crown-6
keywords: EPR; catecholamines; chemiluminescence; scavenging capacity; superoxide anion radical