1. A 2-day-old prem ature m ale baby, born by norm al vaginal delivery, presented w ith severe cyanosis. Chest x-rays and echocardiography con rm ed the diagnosis of congenital transposition of the...

1. A 2-day-old prem ature m ale baby, born by norm al vaginal delivery, presented w ith severe cyanosis. Chest x-rays and echocardiography con rm ed the diagnosis of congenital transposition of the great arteries, and the baby was scheduled for surgery. W hich of the follow ing drugs was m ost likely adm inistered by intravenous infusion to the baby until surgery? A. Indom ethacin B. Alprostadil C. Dinoprostone D. Latanoprost E. Misoprostol 2. A 35-year-old wom an was seen at the clinic because of progressive exertional dyspnea and arthralgias. Further exam s led to the diagnosis of prim ary pulm onary hypertension, and an intravenous infusion of epoprostenol was started. Which of the follow ing m olecular actions m ost likely m ediated the therapeutic e cacy of the drug in the patient’s disease? A. Blockade of Ca2+ channels B. Activation of ß2 adrenoceptors C. Opening of K+ channels D. Blockade of a1 adrenoceptors E. Activation of prostaglandin I2 receptors