The mechanism of action of sodium nitroprusside is:: (A) Increased cAMP, (B) Stimulation of guanylate cyclase, (C) Calcium channel blockage, (D) K+ channel opener
Answer is B. Ans. (B) Stimulation of guanylate cyclase(Ref: KDT 8th/e p544)Sodium nitroprusside acts by releasing nitric oxide (NO). This stimulates guanylate cyclase and results in the elevation of cGMP, which is a potent vasodilator.