Nitric oxide is effective in the treatment of pulmonary hypertension in neonates because it causes which of the following?

a. Peripheral vasocon-striction c. Platelet adhesion
b. Macrophage cyto-toxicity d. Vasodilatation

ANS: D
Nitric oxide is used for the treatment of pulmonary hypertension in neonates because it promotes pulmonary vasodilatation. Other effects of nitric oxide include macrophage cytotoxicity and platelet adhesion.