Description
Test Principle: This assay employs a two-site sandwich ELISA to quantitate ANG-2 in samples. An antibody specific for ANG-2 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any ANG-2 present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for ANG-2 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 ANG-2 bound in the initial step. The color development is stopped and the intensity of the color is measured.
Overview: Angiotensin I is converted to angiotensin II through removal of two terminal residues by the enzyme Angiotensin-converting enzyme (ACE, or kinase), which is found predominantly in the capillaries of the lung. ACE is actually found all over the body, but has its highest density in the lung due to the high density of capillary beds there. Angiotensin II acts as an endocrine, autocrine/paracrine, and intracrine hormone. ACE is a target for inactivation by ACE inhibitor drugs, which decrease the rate of angiotensin II production. Angiotensin II increases blood pressure by stimulating the Gq protein in vascular smooth muscle cells. ACE inhibitor drugs are major drugs against hypertension. Other cleavage products of ACE, 7 or 9 amino acids long, are also known; they have differential affinity for angiotensin receptors, although their exact role is still unclear