Endothelin (ET) is a potent vasoconstrictor peptide produced by vascular endothelial cells. Three distinct human endothelin genes were cloned and analysed. The results demonstrated that there were three distinct mRNAs for ET and that TPA-responsive element, mRNA stabilizing sequence, motifs for binding site of nuclear factor 1 and acute phase reactant regulatory elements were recognized in preproform ET-1 gene.