Endothelins are among the most potent vasoconstrictor proteins known. Overexpression of endothelins contributes to hypertension and heart disease. Three isoforms are known, each containing 21 amino acids: endothelin-1 (ET-1), endothelin-2 (ET-2) and endothelin-3 (ET-3). All three isoforms are encoded by a 38-amino-acid precursor known as big endothelin. Endothelins are expressed in many tissues, including lung, kidney, brain, pituitary and placenta.
These kits are solid-phase sandwich ELISAs using two antibodies that are highly specific to human or rat big ET-1 protein; one is precoated on the ELISA plate, and the other is HRP-conjugated. These kits can be used to measure soluble human or rat big ET-1 protein in serum, EDTA-plasma, cell culture supernatants or tissue extracts.