Affiliation:
1. Medical Research Centre1 and
2. Department of Renal Medicine,2 City Hospital, Nottingham, United Kingdom
Abstract
ABSTRACT
Peritoneal dialysis effluent (PDE) contains a low-molecular-weight solute that will activate and prime the NADPH oxidase of human neutrophils via a phospholipase A
2
(PLA
2
)-dependent mechanism. Since the products of PLA
2
are known to activate and prime the oxidase we have investigated their role in the dialysis effluent-mediated activation and priming of human neutrophils. NADPH oxidase activity of PDE-primed and -unprimed neutrophils was measured by lucigenin-enhanced chemiluminescence in the presence of known inhibitors of the arachidonic acid cascade. Incubation of neutrophils with the nonselective PLA
2
inhibitor quinacrine (0 to 100 μM) reduced oxidase activity in both primed and unprimed cells. Furthermore, primed cells were more sensitive to the action of quinacrine than were unprimed cells. We were unable to determine the relative roles of secretory PLA
2
(
s
PLA
2
) and cytosolic PLA
2
(
c
PLA
2
) since the selective
s
PLA
2
inhibitor scalaradial (0 to 100 μM) inhibited oxidase activity in both groups of cells by similar degrees, while the specific
c
PLA
2
inhibitor AACO-CF
3
(0 to 50 μM) failed to affect activity in either group. Inhibition of platelet-activating factor (PAF), cycloxygenase, and 5-lipoxygenase-activating protein by hexanolamino-PAF (0 to 25 μM), flurbiprofen (0 to 25 μM), and MK886 (0 to 5 μM), respectively, had no effect upon oxidase activity. However, the direct inhibition of 5-lipoxygenase by caffeic acid or lipoxin A
4
resulted in a similar concentration-dependent attenuation of oxidase activity in both primed and unprimed cells. Leukotriene B
4
(LTB
4
) release from primed neutrophils was comparable to that from unprimed cells with the exception of phorbol myristate acetate-stimulated cells, which released fivefold more LTB
4
than control. Taken together, these results suggest that it is arachidonic acid per se, and not its metabolites, that is important in priming of the neutrophil NADPH oxidase by dialysis effluent.
Publisher
American Society for Microbiology
Subject
Microbiology (medical),Clinical Biochemistry,Immunology,Immunology and Allergy
Reference52 articles.
1. Inhibition of neutrophil respiratory burst and degranulation responses to platelet-activating factor by antagonists WEB 2086, CV 6209 and CV 3988.;Bates E. J.;Int. Arch. Allergy Immunol.,1992
2. TNFα priming of PLA2 activation in human neutrophils—an alternative mechanism of priming.;Bauldry S. A.;J. Immunol.,1991
3. PLA2 activation in human neutrophils.;Bauldry S. A.;J. Biol. Chem.,1988
4. Boyum A. 1968. Isolation of mononuclear cells and granulocytes from human blood. Scand. J. Clin. Lab. Investig. 21 (Suppl. 97):77–89.
5. Serum coated zymosan stimulates the synthesis of LTB4 in human PMN. Inhibition by cAMP.;Classon H.-E.;Biochem. Biophys. Res. Commun.,1981
Cited by
24 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献