Modulation of rat peripheral polymorphonuclear leukocyte response by nitric oxide and arginine

Abstract

The effect of nitric oxide (NO) on the luminol-dependent chemiluminescence (LCL) response of rat polymorphonuclear leukocytes (PMNLs) was analyzed by using sodium nitroprusside (SNP), a NO donor, and L-arginine (L-arg), a NO precursor. A significant reduction in the LCL intensity was observed in presence of SNP (100 mumol/L) or L-arg (5 or 10 mmol/L) in arachidonic acid (AA) phorbol ester (PMA) and formyl- methionyl-leucyl-phenylalanine stimulated PMNLs. However, opsonized zymosan-induced LCL was not attenuated significantly. Reduction in hydroxyl radical and superoxide generation was also observed in SNP- or L-arg-pretreated cells. D-Arg (10 mmol/L) pretreatment did not inhibit PMNLs' LCL response. Furthermore, methylene blue (5 mumol/L) and L-NG- mono methyl-L-arginine (100 or 300 mumol/L) significantly attenuated the LCL response, as induced by various agonists. Cyclic GMP did not alter the reactive oxygen species generation from rat PMNLs. In addition, AA-induced release of myeloperoxidase, a marker of azurophilic granules, was found to be enhanced in L-arg- (10 mmol/L) pretreated PMNLs. The results suggest that NO inhibits free radical generation from rat PMNLs.

Interaction of nitric oxide synthase inhibitors and their D‐enantiomers with rat neutrophil luminol dependent chemiluminescence response

“…Such an observation has not been published previously and indicates that these agents should be used with caution to delineate the role of NO in PMNLs free radical generation estimated by luminol. In our previous study, while investigating the role of endogenous as well as exogenous NO on rat PMNLs free radical generation, we observed that NO from both sources inhibited, as well as scavenged, the free radicals (Seth et al, 1994). Similar observations were also obtained by others in human PMNLs (Rubanyi et al, 1991;Clancy et al, 1992).…”

“…by use of a dual channel lumiaggregometer (Model 560 Chronolog Corp. Havertown, PA, U.S.A.) and has been presented as LCL and LUCDCL units. The LCL or LUCDCL units have been defined as the maximum output (obtained from stimulated PMNLs) divided by the 'gain setting' of the instrument at the time of response (Seth et al, 1994). The assay mixture (1000 pl) contained 1-5 x 106 PMNLs, 10 giM luminol or 50 gM of lucigenin, test substance (L-and D-arginine analogues) and FMLP (1 x 10-6 M) or AA (1 x I0-5 M).…”

“…Most of the NOS inhibitors are arginine derivatives and are known to be substrate analogue inhibitors of NOS. D-Arginine, an enantiomer of L-arginine which is not utilized by NOS has been used to establish the specificity of the response being analyzed Seth et al, 1994).…”

“…Many workers have used analogues of L-arginine to demonstrate the role of NO in polymorphonuclear leukocyte (PMNL) functions such as free radical generation, chemotaxis, aggregation, adhesion and microbicidal activity (Kaplan et al, 1989;Rubanyi et al, 1991;Kubes et al, 1991;Malawista et al, 1992;Belenky et al, 1993). Recently inhibition of free radical generation from rat PMNLs by both endogenous and exogenous nitric oxide has been demonstrated by us (Seth et al, 1994). However, we also observed that the NOS inhibitors (NG-nitro-L-arginine methyl ester (L-NAME) and N0-monomethyl-L-arginine (L-NMMA) inhibited free radical generation from rat PMNLs, suggesting nonspecificity of these agents.…”

Ascorbate-mediated enhancement of reactive oxygen species generation from polymorphonuclear leukocytes: modulatory effect of nitric oxide

“…In addition to ROS scavenging, NO attenuated NADPH oxidase activity [5] and inhibited ROS generation, and a NO-dependent increase in the intracellular calcium augmented ROS generation [4]. NO-mediated modulation of ROS generation has also been demonstrated in the conditions associated with the increased accumulation of NO, such as hypoxia-reoxygenation [1,4,6] and lipopolysaccharide treatment [7].…”