During a cardiovascular examination,a patient has a resting heart rate of 65 beats/minute and a blood pressure of 100/70 mm Hg in the supine position.In the upright position at steady state,the patient's heart rate is 74 beats/minute,and the blood pressure is 105/70 mm Hg. Agents that increase intracellular cyclic adenosine monophosphate (cAMP),such as β-adrenergic agonists,have a potent vasodilator effect by:
A)Increasing nitric oxide production in smooth muscle. B)Stimulating guanylate cyclase activity in endothelial cells. C)Reducing myosin light-chain kinase (MLCK)activity. D)Suppressing calcium entry into smooth muscle cells. E)Reducing the synthesis of guanosine monophosphate (cGMP)in smooth muscle