Chemical Formula: C5FeN6O

Nitroprusside

C5FeN6O (215.948298)

Nitroprusside is only found in individuals that have used or taken this drug. It serves as a source of nitric oxide, a potent peripheral vasodilator that affects both arterioles and venules (venules more than arterioles). Nitroprusside is often administered intravenously to patients who are experiencing a hypertensive emergency. [Wikipedia]One molecule of sodium nitroprusside is metabolized by combination with hemoglobin to produce one molecule of cyanmethemoglobin and four CN- ions; methemoglobin, obtained from hemoglobin, can sequester cyanide as cyanmethemoglobin; thiosulfate reacts with cyanide to produce thiocyanate; thiocyanate is eliminated in the urine; cyanide not otherwise removed binds to cytochromes. Cyanide ion is normally found in serum; it is derived from dietary substrates and from tobacco smoke. Cyanide binds avidly (but reversibly) to ferric ion (Fe+++), most body stores of which are found in erythrocyte methemoglobin (metHgb) and in mitochondrial cytochromes. When CN is infused or generated within the bloodstream, essentially all of it is bound to methemoglobin until intraerythrocytic methemoglobin has been saturated.Once activated to NO, it activates guanylate cyclase in vascular smooth muscle and increases intracellular production of cGMP. cGMP stimulates calcium movement from the cytoplasm to the endoplasmic reticulum and reduces calcium available to bind with calmodulin. This eventually leads to vascular smooth muscle relaxation and vessel dilatation.