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Endothelin-1: Potent Vasoconstrictor

Endothelin-1 (ET-1), a peptide of 21 amino acid residues, is a pleiotropic molecule known for its action as a potent vasoconstrictor. ET-1 is one of a family of three proteins encoded by distinct genes that also includes Endothelin-2 (ET-2) and Endothelin-3 (ET-3). ET-2 and ET-3 differ from ET-1 by 2 and 6 amino acids, respectively. All members of the Endothelin family contain two essential disulfide bridges and six conserved amino acid residues at the C-terminus. Human ET-1 is initially synthesized as a pre-pro-polypeptide of 212 amino acids. It is proteolytically cleaved by a signal peptidase to produce pro-ET-1, and further processed by a Furin-like protease to yield Big ET-1. Big ET-1 is then cleaved by the membrane-bound metalloprotease Endothelin-converting enzyme (ECE-1), producing the potent mature form, ET-1. The vascular endothelium is an abundant source of ET-1. It may also be expressed by leukocytes, smooth muscle cells, mesangial cells, cardiac myocytes, and astrocytes. ET-1 can be induced in endothelial cells by many factors including mechanical stimulation, various hormones, and pro-inflammatory cytokines. Production is inhibited by nitric oxide (NO), cyclic nucleotides, prostacyclin, and atrial natriuretic peptide (ANP).

Human Endothelin 1

ET-1 also stimulates cardiac contraction and the growth of cardiac myocytes, regulates the release of vasoactive substances, and stimulates smooth muscle cell mitogenesis. ET-1 may control inflammatory responses by promoting the adhesion and migration of neutrophils and stimulating the production of pro-inflammatory cytokines. It has also been implicated in cancer progression, regulating the proliferation and migration of tumor cells and acting as a pro-angiogenic factor. ET-1 has putative roles in other pathologies including septic shock, atherosclerosis, heart failure, renal insufficiency, pulmonary hypertension, and cerebrovascular conditions associated with subarachnoid hemorrhage.

Our New Endothelin-1 (ET-1) Enzyme Immunoassay Kit (K045-H1), is the world’s most sensitive ET-1 kit. It is designed to quantitatively measure ET-1 present in serum and plasma from a variety of species, and tissue culture media samples. An ET-1 standard is provided to generate a standard curve for the assay and all samples should be read off the standard curve. Standards or diluted samples are pipetted into a clear microtiter plate coated with an antibody to capture ET-1. After a 60 minute incubation, the plate is washed and a peroxidase conjugated ET-1 antibody is added. The plate is incubated for 60 minutes and washed. Substrate is then added to the plate, which reacts with the bound ET-1 conjugated antibody. After a third incubation, the reaction is stopped and the intensity of the generated color is detected in a microtiter plate reader capable of measuring 450 nm wavelength. The concentration of the ET-1 in the sample is calculated, after making suitable correction for dilution, using software available with most plate readers.

  • MULTI-SPECIES – human, bovine, porcine, dog, rat and mouse
  • SENSITIVITY – Measure less than 30 fg ET-1/sample
  • SIMPLE – No C18 Column Purifications
  • ECONOMICAL – Extraction Solution Included
  • SAMPLES/KIT – 38 in Duplicate
  • STABLE – 4°C Stability
Typical Standard Curve

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