Background:

Sodium Nitroprusside is a potent nitric oxide (NO) donor.

NO is an important cellular signaling molecule and a powerful vasodilator in the blood, thus resulting in vasodilation and increasing blood flow.

Sodium nitroprusside is a potent nitric oxide (NO) donor by releasing NO into blood. Sodium nitroprusside inhibited the contractile response of Ca2+-depleted depolarized rat aorta to extra-cellular Ca2+ and Ca2+ uptake induced by K+. Also, sodium nitroprusside decreased the rapid contraction phase induced by noradrenaline [1]. In isolated bull veins, sodium nitroprusside relaxed bull veins contraction induced by noradrenaline in a dose-dependent way [2]. In platelet-rich plasmas (PRP), sodium nitroprusside significantly inhibited platelets aggregation and also inhibited ADP and ATP release from platelets induced by collagen, which might be due to contraction of platelet smooth muscle-like protein [3].

In patients with total hip replacement under anesthesia, sodium nitroprusside (100 μg/ml) induced hypotension and reduced surgical blood loss [4].

参考文献:
[1].  Kreye VA, Baron GD, Lüth JB, et al. Mode of action of sodium nitroprusside on vascular smooth muscle. Naunyn Schmiedebergs Arch Pharmacol, 1975, 288(4): 381-402.
[2].  Gmeiner R, Riedl J, Baumgartner H. Effect of sodium nitroprusside on myocardial performance and venous tone. Eur J Pharmacol, 1975, 31(2): 287-291.
[3].  Saxon A, Kattlove HE. Platelet inhibition by sodium nitroprusside, a smooth muscle inhibitor. Blood, 1976, 47(6): 957-961.
[4].  Lawson NW, Thompson DS, Nelson CL, et al. A dosage nomogram for sodium nitroprusside-induced hypotension under anesthesia. Anesth Analg, 1976, 55(4): 574-580.