title: The combined luminol/isoluminol chemiluminescence method for differentiating between extracellular and intracellular oxidant production by neutrophils.
abstract: To address the question why isoluminol, but not luminol, failed to detect oxidants produced intracellularly, differences between these luminophores were investigated with respect to physicochemical parameters and the character of chemiluminescence signal. Our results showed the isoluminol molecule to be more polar, more hydrophilic and possessing lower ability to form intramolecular bonds than the luminol molecule. Therefore, isoluminol: (i) only slightly pervaded biological membranes; (ii) depended essentially on extracellular peroxidase; (iii) did not produce chemiluminescence in the presence of extracellular scavengers; and (iv) it could be considered a specific detector of extracellular radicals. On the other hand, the physicochemical parameters of luminol and partial resistance of its chemiluminescence to the effect of extracellular inhibitors proved the lipo/hydrophilic character of this luminophore and thus its ability to interact with radicals both outside and inside of cells. The luminol chemiluminescence measured in the presence of extracellular scavengers and the isoluminol chemiluminescence were used with the intention to differentiate the effects of two antihistamine drugs on intra- and extracellular radical formation. In activated human neutrophils, brompheniramine inhibited the extracellular and potentiated the intracellular part of chemiluminescence signal, whereas a reducing effect of loratadine was observed in both compartments.
authors.affiliation: Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Slovak Republic. Viera.Jancinova@savba.sk
authors.forename: Viera
authors.initials: V
authors.lastname: Jancinová
authors.forename: Katarína
authors.initials: K
authors.lastname: Drábiková
authors.forename: Radomír
authors.initials: R
authors.lastname: Nosál
authors.forename: Lucia
authors.initials: L
authors.lastname: Racková
authors.forename: Magdaléna
authors.initials: M
authors.lastname: Májeková
authors.forename: Dagmar
authors.initials: D
authors.lastname: Holománová
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D001977:Brompheniramine / Q000494:pharmacology; D005609:Free Radicals; D006634:Histamine H1 Antagonists / Q000737:chemistry / Q000302:isolation & purification; D006801:Humans; D017336:Loratadine / Q000737:chemistry; D008163:Luminescent Measurements / Q000379:methods*; D008165:Luminol / Q000031:analogs & derivatives* / Q000737:chemistry*; D008956:Models, Chemical; D009504:Neutrophils / Q000378:metabolism*; D016877:Oxidants / Q000737:chemistry*; D010544:Peroxidases / Q000737:chemistry
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D006634:Histamine H1 Antagonists; D016877:Oxidants; C032487:isoluminol; D008165:Luminol; D017336:Loratadine; D010544:Peroxidases; D001977:Brompheniramine