Biological activity of nitric oxide in the plasmatic compartment

摘要: There exist reaction products of nitric oxide (NO) with blood that conserve its bioactivity and transduce an endocrine vasomotor function under certain conditions. Although S-nitrosated albumin has been considered the major species subserving this activity, recent data suggest additional NO species, such as nitrite, nitrated lipids, N-nitrosamine, iron-nitrosyl complexes, may contribute. We therefore examined end reactions in plasma vitro vivo by using reductive chemiluminescent assays electron paramagnetic resonance spectroscopy. found complexes previously to be were <10 nM after elimination nitrite mercury-stable, consistent or N-nitrosamine complex. During clinical gas inhalation protocols donor treatment human plasma, S-nitroso-albumin did not form exposure <2 microM, but methemoglobin was detectable Consistent formation methemoglobin, consume approximately 2 microM at a rate equivalent hemoglobin. This consumption mediated haptoglobin-hemoglobin limited slower pathways required for S-nitrosation. These high-affinity, metal-based complex modulate plasmatic limit S-nitrosation low flux. The studies further alternative N-nitrosamines, iron-nitrosyls, should evaluated transport along vasculature.