27. Mechanism of Action of Vasodilators MECHANISM EXAMPLES Release of nitric oxide from drug or endothelium NItroprusside Hydralazine Hyperpolarization of vascular smooth muscle thru opening of K channels NImoxidil Diazepoxide Reudction of Calcium Influx Verapa,o;. Diltiazem Nifedipine Activation of dopamine receptors Fenoldopam