The heart is commonly understood as a muscular pump circulating blood throughout the body. However, it also performs an important endocrine function. Specialized heart muscle cells produce peptide hormones that communicate with distant organs and help regulate cardiovascular balance. Among the most important of these are atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP). ANP is released by cells in the atria, the upper chambers of the heart, when their walls are stretched. BNP is produced mainly by ventricular muscle cells, particularly when the ventricles experience increased mechanical stress. These signals respond to changes in the heart's workload and circulating volume. Once released, natriuretic peptides interact with specific receptors in different tissues. ANP and BNP activate natriuretic peptide receptor A, which stimulates the production of cyclic guanosine monophosphate, known as cGMP. This molecule acts as a second messenger, carrying the signal inside cells and activating downstream processes. Their effects include relaxation of blood vessels, increased sodium excretion, and modulation of hormonal systems involved in blood pressure regulation. Through these mechanisms, they counterbalance signals that promote fluid retention and increased vascular resistance. These hormones also have an important role in modern cardiovascular medicine. BNP and its fragment NT-proBNP can be measured in blood tests and used as biomarkers when evaluating suspected heart failure. Their concentrations provide useful information about cardiac stress, although results must be interpreted alongside clinical findings. The study of natriuretic peptides reveals an important aspect of human physiology: the heart does much more than move blood. It also acts as a signaling organ, communicating with the rest of the body through precisely regulated molecular messages. https://peptidessacramento.net/