Synthesis of nitric oxide from l-arginine by neutrophils. Release and interaction with superoxide anion

Abstract

Stimulated rat peritoneal neutrophils release a platelet inhibitory factor with the pharmacological properties of NO. This release is inhibited by N0-monomethyl-L-arginine and L-canavanine, indicating that it occurs through a mechanism similar to that in vascular endothelial cells and macrophages. As the degree of stimulation increases, the factor released is progressively inactivated by concomitant release of superoxide anions.

Interactive role of nitric oxide and superoxide anion in neutrophil-mediated endothelial cell injury

“…In this context, the interaction of NO with oxygen free radicals, particularly with O 2 Ϫ , is of significance. The capacity of SOD to (1) reverse adhesion in mesentric venules caused by ischemia-reperfusion [34], (2) attenuate the effect of xanthine-xanthine oxidase-induced adherence of PMN [35], and (3) potentiate inhibition of PMN aggregation [36], are a few observations supporting the view that O 2 Ϫ modulates leukocyte adhesion to EC. Although the exact mechanism by which O 2 Ϫ mediates PMN-EC adhesion is poorly defined, it may be speculated that O 2 Ϫ neutralizes the anti-adhesive substance released from EC.…”

“…In this study, the presence of NO in the medium (with the addition of SNAP/L-arginine) decreased the EC injury, suggesting that NO prevents PMN-mediated injury. The protective effect of NO has been ascribed to its inhibition of inflammatory cell margination and function [36]. In addition, NO may have a protective role by either scavenging the O 2 Ϫ radicals [39] or redirecting O 2 Ϫ -mediated cytotoxic reactions to other cytotoxic pathways [39,40].…”

The hepatic circulation in health and disease: Report of a single-topic symposium

“…44 Proposed protective effects include regulation of blood flow, antimicrobial activity, and regulation of cell proliferation. 45 Experimental evidence suggests that NO protects hepatocytes from injury and may in fact be anti-apoptotic. Additionally, hepatocytes are highly resistant to the potential toxic effects of NO, itself.…”

Ischaemia-reperfusion injury in photodynamic therapy-treated mouse tumours

“…NO reacts rapidly with superoxide forming peroxynitrite anion (Blough and Zafiriou, 1985;McCall et al, 1989) and this can result in superoxide detoxification (Wink et al, 2001). This element may contribute to the observed tendency of an increased resistance to PDT of tumours characterised by elevated intrinsic NO production (Korbelik et al, 2000).…”