期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：1
页码：336-341
DOI：10.1073/pnas.0234600100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Endothelial NO production results in local formation of adducts that may act as storage forms of NO. Because little is known about their chemical nature, concentrations, and possible role in vascular biology, we sought to characterize those species basally present in rat aorta, using two independent approaches. In the first approach, tissue homogenates were analyzed by using chemiluminescence- and ion-chromatography-based techniques that allow trace-level quantification of NO-related compounds in complex biological matrices. In the second approach, NO stores were characterized by their ability to release NO when illuminated with light and subsequently relax vascular smooth muscle (photorelaxation). The latter included a careful assessment of action spectra for photorelaxation, taking into account the light-scattering properties of the tissue and the storage depletion rates induced by exposure to controlled levels of light. Biochemical analyses revealed that aortic tissues contained 10 {+/-} 1 {micro}M nitrite, 42 {+/-} 7 {micro}M nitrate, 40 {+/-} 6 nM S-nitroso, and 33 {+/-} 6 nM N-nitroso compounds (n = 4-8). The functional data obtained suggest that the NO photolytically released in the tissue originated from species with photophysical properties similar to those reported for low-molecular-weight S-nitrosothiols, as well as from nitrite. The relative contribution of these potential NO stores to the extent of photorelaxation was consistent with their concentrations detected biochemically in vascular tissue when their photoactivity was taken into account. We conclude that intravascular nitroso species and nitrite both have the potential to release physiologically relevant quantities of NO independent of enzymatic control by NO synthase.
