Luminol-dependent chemiluminescence is related to the extracellularly released reactive oxygen intermediates in the case of rat neutrophils activated by formyl-methionyl-leucyl-phenylalanine.
Luminol is a non-radical-specific amplifying molecule which produces light upon interaction with various reactive oxygen intermediates (ROIs). ROI production of rat peritoneal polymorphonuclear leukocytes (PMNLs) elicited by 2.3 microM formyl-methionyl-leucyl-phenylalanine (fMLP) results in a biphasic luminol-dependent chemiluminescence (LDCL) signal. Whereas ROIs are also produced intracellularly, as judged by flow cytometry, addition of non-membrane-permeable catalase reduces the first and second phases of the LDCL signal to around 3% and less than 3%, respectively. This suggests that in the case of fMLP-stimulated rat PMNLs, the LDCL signal is related to the ROIs in the extracellular medium and hydrogen peroxide has a key role in the formation of the LDCL signal. In the presence of the non-specific myeloperoxidase inhibitor Na-azide, the first phase of the LDCL signal decreases slightly (87+/-8%), while the second phase almost disappears (< 3%), indicating the myeloperoxidase dependence of the second phase. The hydroxyl radical scavenger histidine results in an 84+/-4% and a 71+/-4% decrease in the intensity of the first and second phases, respectively. Based on these data, it is concluded that hydrogen peroxide might be the source of hydroxyl radicals directly oxidizing luminol in the first phase of the LDCL signal, while in the second phase it serves as a substrate of myeloperoxidase in the peroxidation reaction of the luminol.
Németh
Krisztina
K
Department of Pathophysiology, Institute of Health Protection, Hungarian Defence Forces, Budapest.
Fûrész
József
J
Csikor
Katalin
K
Schweitzer
Katalin
K
Lakatos
Susan
S
D000818:Animals; D005110:Extracellular Space / Q000378:metabolism*; D016166:Free Radical Scavengers / Q000494:pharmacology; D006639:Histidine / Q000494:pharmacology; D017665:Hydroxyl Radical / Q000037:antagonists & inhibitors; D007202:Indicators and Reagents; D008163:Luminescent Measurements; D008165:Luminol; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D018375:Neutrophil Activation / Q000502:physiology*; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology*; D009195:Peroxidase / Q000502:physiology; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*
D016166:Free Radical Scavengers; D007202:Indicators and Reagents; D017382:Reactive Oxygen Species; D017665:Hydroxyl Radical; D006639:Histidine; D009240:N-Formylmethionine Leucyl-Phenylalanine; D008165:Luminol; D009195:Peroxidase