Nitroprusside: A Potpourri of Biologically Reactive Intermediates
Sodium nitroprusside, Na2[Fe(CN)5NO], (SNP) has been recognized as a potent, directly acting vasodilator for over a half-century. More recently, it has been found also to inhibit blood platelet aggregation and adhesion. These biologicial activities are ascribed to the nitrosyl ligand on SNP which is thought to activate guanylate cyclase by binding to its critical heme group. c-GMP in turn initiates a cascade of kinase reactions which result in the utimate biological effects. Thus, SNP is one of the compounds known as the nitric oxide (NO) vasodilators (Ignarro, 1989) which mimic the effects of the so-called endothelium-derived relaxing factor (Furchgott and Zawadzki, 1980), an endogenous mediator which many are convinced is identical to NO. The same or a similar factor is believed to play in role in excitatory amino acid transmission in the central nervous system, and to be the cytotoxic factor synthesized by neutrophils and macrophages (Collier and Valiance, 1989).
KeywordsNitric Oxide Electron Paramagnetic Resonance Methylene Blue Sodium Nitroprusside Guanylate Cyclase
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