Human Hormones

Atrial Natriuretic Peptide (ANP), also known as atriopeptin, is a hormone found in the human body. It is secreted by the atrial myocytes in the heart. ANP is a 28 amino acid peptide with a 17AA ring. It is classified as a peptide hormone.
Secretion and Production

ANP is produced in and secreted from the atrial myocytes in the heart. Several things cause secretion of ANP, including stretching, raised sodium concentration, release of Angiotensin-II, and release of Endothelin. ANP was first discovered in 1981 by a research team led by Mercedes Kuroski de Bold.

Overall, secretion of ANP has the effects of reducing blood volume, therefore reducing venous pressure, cardiac output, and arterial blood pressure. In the kidneys, ANP secretion results in greater excretion of sodium and water, a decrease in sodium reabsorption, and the inhibition of renin secretion. In the arteries and veins, ANP relaxes smooth muscles by elevating levels of cGMP and inhibiting the effects of catecholamines. Additionally, ANP reduces aldosterone production.
Pharmacological Uses

Though synthetic ANP is still being researched for its potential use as a drug, it has been synthesized. Few studies have been conducted as to the uses of ANP as a drug in humans, but it has been shown in studies to be of benefit to patients with cardiac failure. Patients who have undergone heart surgery have been shown to have a lower concentration of ANP than in patients with healthy hearts. Therefore, synthetic ANP, when administered intravenously, may be of benefit in restoring normal heart function and blood pressure in these patients.