In contrast to hydralazine, minoxidil, and diazoxide, sodium nitroprusside relaxes venules as well as arteri-oles. Thus, it decreases both peripheral vascular resistance and venous return to the heart. This action limits the increase in cardiac output that normally follows vasodilator therapy. Sodium nitroprusside does not inhibit sympathetic reflexes, so heart rate may increase following its administration even though cardiac output is not increased. Renal blood flow remains largely unaffected by sodium nitroprusside, because the decrease in renal vascular resistance is proportional to the decrease in mean arterial pressure. As with all vasodilators, plasma renin activity increases.
that this therapeutic approach corrects the cause of the elevated pressure. Only in a few specific cases, such as pheochromocytoma, can hypertension be directly related to abnormalities in the functioning of the sympathetic system.
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...