Adrenomedullin is a short chain of amino acids, or human protein, called a peptide, which is found in the blood. This peptide is linked to pheochromocytoma, a rare neoroendocrine tumor of the adrenal medulla that fails to coil after birth. Such tumors are said to excrete excessive amounts of epinephrin, or the catecholamine known as adrenaline.
Composed of 52 amino acids, adrenomedullin was first discovered in 1993. It is said to lower blood pressure in the lungs, reduce inflammation and reduce the leaking of fluid into the lungs. This natural peptide also plays significant roles in preserving and regulating cardiovascular and pulmonary functions by improving ailments such chronic obstructive pulmonary disease, hypertension and myocardial infarctions. Adrenomedullin is also thought to inhibit the proliferation of cancer cells.
This peptide is considered one of the most powerful endogenous vasodilatory peptides in the body. In other words, adrenomedullin is one of the most potent internal agents that causes dilation within the body. For this reason, adrenomedullin has the ability to relax vascular tone and is believed to increase the resistance of cells to oxidative stress.
Adrenomedullin can be found in the single chromosome 11. Initially coded to form a 185-amino acid precursor peptide, the adrenomedullin gene can be cut off to form a number of peptides. The mature 52 amino acid human adrenomedullin, however, is structurally similar to the calcitonin family of regulatory peptides.
These calcitonin peptides are known to participate in calcium and phosperous metabolism. The major source of calcitonin is found in the thyroid gland but can be synthesized in various tissues such as the lungs. These peptides are thought to function in the nervous and vascular systems.
Adrenomedullin is suggested to mediate action via the interaction of both calcitonin receptor-like and receptor activity-modifying proteins. The stimulation of adrenomedullin receptors thus produces cellular forms of cyclic adrenosine monophosphate (cAMP). These messengers are used for transferring the effects of hormones such as adrenaline.
