Intra- and extracellular events in luminol-dependent chemiluminescence of polymorphonuclear leukocytes

Abstract

When polymorphonuclear leukocytes (PMNL) and soluble or particulate matter interact, the cells produce chemiluminescence. Luminol-dependent light emission from PMNL is linked to the myeloperoxidase (MPO)-H202 system. Light emission from a cell-free MPO-H202 system was found to be totally inhibited by human serum albumin (HSA), and since HSA is a large molecular protein that does not readily gain access to intracellular sites of PMNL, it could be used to determine the importance of extra-and intracellular events in PMNL chemiluminescence. In studies with cells from an MPO-deficient patient, we found that HSA inhibited more than 90% of extracellularly produced chemiluminescence. The chemotactic peptide formylmethionylleucyl-phenylalanine induced a two-peak chemiluminescence response in normal PMNL, and addition of HSA reduced the first peak, whereas the second peak was unaffected. This result indicated that the first peak was a result of extracellular reactions and the second peak was a result of intracellular reactions of the MPO-H202 system. Most of the phorbol myristate acetate-induced response in normal PMNL was due to intracellular events. Furthermore, chemiluminescence of intracellular origin seems to be limited not by generation of oxidative metabolites but by diffusion of luminol into the cells.

Activation of mouse protease‐activated receptor‐2 induces lymphocyte adhesion and generation of reactive oxygen species

“…The luminol molecule reacts with ROS to form excited aminophthalate anions that decay to the ground state with the release of energy in the form of light, which is measured as chemiluminescence (Briheim et al, 1984;Lundqvist and Dahlgren, 1996). The current study has shown that mouse lymphocytes are capable of generating a reproducible increase in the chemiluminescence signal when stimulated with PMA, PAF or trypsin.…”

Antioxidant activity of hyaluronic acid investigated by means of chemiluminescence of equine neutrophil bursts and electron paramagnetic resonance spectroscopy

“…PMNs and the ROS/RNS released by PMNs are strictly interlinked factors involved in the pathogenesis and progression of human inflammatory airway diseases such as chronic obstructive pulmonary disease (COPD), asthma, airway infections and cystic fibrosis (Levine, 1995;Ichinose et al, 2000), as well as equine RAO, EIPH and IAD; therefore, the aim of this study was to examine whether a preparation of hyaluronic acid interferes with ROS and RNS during the course of equine PMN respiratory bursts, and to establish the lowest concentration at which it still has antioxidant activity by means of luminol-amplified chemiluminescence (LACL). LACL is a method that has been widely used to detect the PMN production of ROS/RNS under various conditions (Briheim et al, 1984;Robinson et al, 1984).…”

Stimulation of reactive oxidant production in neutrophils by soluble and insoluble immune complexes occurs via different receptors/signal transduction systems

“…Indeed, immune aggregates or complexes present within synovial fluid can activate reactive oxidant production by blood neutrophils in vitro [12][13][14]. It is now appreciated that neutrophils can generate reactive oxidants both intracellularly and extracellularly [15][16][17][18] and clearly these events are likely to have different patho-physiological consequences. Whilst intracellular oxidant production (i.e.…”