Atrial natriuretic peptide (ANP) is a 28-amino acid peptide hormone secreted by cardiac myocytes of the atrium. ANP plays an important role in the homeostatic regulation of body water, sodium, potassium and fat, by acting to reduce the water, sodium and adipose loads on the circulatory system, thus reducing blood pressure.

ANP peptide contains a 17-amino acid ring which is formed by a disulfide bond between two cysteine residues at positions 7 and 23. ANP is closely related to BNP (brain natriuretic peptide) and CNP (C-type natriuretic peptide), which all share the same amino acid ring.

The mechanism of ANP-induced vasodilatation is through binding to a specific set of ANP receptors. Receptor-agonist binding causes a reduction in blood volume and therefore a reduction in cardiac output and systemic blood pressure. Lipolysis is increased and renal sodium reabsorption is decreased. The overall effect of ANP on the body is to counter increases in blood pressure and volume caused by the renin-angiotensin system.

In addition to its vasodilatation effect, ANP also serves as a adipokine. Studies have shown that ANP Increases the release of free fatty acids from adipose tissue, activates adipocyte plasma membrane NPR-A receptors, and increases intracellular cGMP levels that induce the phosphorylation of a hormone-sensitive lipase and perilipin A.

Standard, Biotinylated Atrial natriuretic peptide, and Positive Control should be stored at -20°C after arrival. Avoid multiple freeze-thaws. The remaining kit components may be stored at 4°C. Opened Microplate Wells and antibody (Item N) may be stored for up to 1 month at 2° to 8°C. Return unused wells to the pouch containing desiccant pack and reseal along entire edge.