As a result of its breakdown to nitric oxide (NO),<unk>  has potent vasodilating effects on arterioles and venules (arterial more than venous), whereas other nitrates exhibit more selectivity for veins (e.g. nitroglycerin).<unk>  breaks down in circulation to release nitric oxide (NO). It does this by binding to oxyhaemoglobin to release cyanide, methaemoglobin and nitric oxide. NO activates guanylate cyclase in vascular smooth muscle and increases intracellular production of cGMP. cGMP activates protein kinase G which activates phosphatases which inactivate myosin light chains. Myosin light chains are involved in smooth muscle contraction. The result is vascular smooth muscle relaxation, which allow vessels to dilate. This mechanism is similar to that of phosphodiesterase 5 (PDE5) inhibitors such as sildenafil (Viagra) and tadalafil (Cialis), which elevate cGMP concentration by inhibiting its degradation by PDE5. A role for NO in various common psychiatric disorders including schizophrenia, bipolar disorder and major depressive disorder has been proposed and supported by several clinical findings. These findings may also implicate the potential of drugs that alter NO signalling such as<unk>  in their treatment. Such a role is also supported by the findings of the recent<unk>  clinical trial.
Sodium nitroprusside
Balsalazide
Adenosine
Ergotamine
Isoprenaline
Dobutamine
Nitroglycerin 
Labetalol