Description
Principle of the assay: This assay employs a two-site sandwich ELISA to quantitative ADM in Human serum, plasma. An antibody specific for ADM has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any ADM present is bound by the immobilized antibody. After removing any unbound substances, a biotin - conjugated antibody specific for ADM is added to the wells. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Following a wash to remove any unbound avidin-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of ADM bound in the initial step. The color development is stopped and the intensity of the color is measured.
Background: Adrenomedullin (ADM or AM) is a peptide hormone that in humans is encoded by the ADM gene. It is an ubiquitously expressed peptide initially isolated from pheochromyctoma, a tumor of the adrenal medulla (hence the name). A second peptide AM2 has been identified, exhibiting a similar functions. It was discovered in 1993. Adrenomedullin consists of 52 amino acids, has 1 intramolecular disulfide bond, and shows a slight homology with the calcitonin gene-related peptide (CGRP). It may function as a hormone in circulation control because it is found in blood in a considerable concentration. The precursor, called preproadrenomedullin, is 185 amino acids long. By RNA-blot analysis, human adrenomedullin mRNA was found to be highly expressed in several tissues. AM was initially identified as a vasodilator, some have cited this as the most potent endogenous vasodilatory peptide found in the body. Differences in opinion regarding the ability of AM to relax vascular tone arises from the differences in the model system used. Other effects of AM include upregulating angiogenesis and increasing the tolerance of cells to oxidative stress and hypoxic injury. AM is seen as a positive influence in diseases such as hypertension, myocardial infarction, chronic obstructive pulmonary disease and other cardiovascular diseases, whereas it can be seen as a negative factor in potentiating the potential of cancerous cells to extend their blood supply and cause cell proliferation