Role of circulating nitrite and S -nitrosohemoglobin in the regulation of regional blood flow in humans

• DOI: 10.1073/pnas.97.21.11482
• Publication Date: 2002-07-26T14:41:48Z
• Authors: Mark T. Gladwin; James H. Shelhamer; Alan N. Schechter; Margaret E. Pease...; Myron A. Waclawiw; Julio A. Panza; Frederick P. Ogni...; Richard O. Cannon
• Keywords: Brachial artery

To determine the relative contributions of endothelial-derived nitric oxide (NO) vs. intravascular nitrogen species in regulation human blood flow, we simultaneously measured forearm flow and arterial venous levels plasma nitrite, LMW-SNOs HMW-SNOs, red cell S-nitrosohemoglobin (SNO-Hb). Measurements were made at rest during regional inhibition NO synthesis, followed by exercise. Surprisingly, found significant circulating arterial-venous nitrite gradients, providing a novel delivery source for NO. Further supporting notion that is bioactive, consumption increased significantly with exercise endothelial synthesis The role S-nitrosothiols SNO-Hb basal vascular tone less certain. We low-molecular-weight undetectable S-nitroso-albumin two logs lower than previously reported. In fact, primarily formed circulation, even synthase inhibition. Whereas was measurable circulation (brachial artery 170 nM whole blood), gradients not significant, from minimal. conclusion, present data suggest (i) bioactive provides gradient NO, (ii) does deliver lungs to tissue but forms peripheral (iii) play minimal tone, stress.