4-Ala-ET-1

**4-Ala-ET-1** is a synthetic peptide analogue of **endothelin-1 (ET-1)** in which four alanine residues substitute specific positions in the parent ET-1 peptide. It is primarily used as a **selective endothelin B receptor (ETB) agonist** in pharmacological research to distinguish biological effects mediated via ETB from those mediated by ETA receptors. Unlike ET-1, 4-Ala-ET-1 does not produce vasoconstriction in arterial smooth muscle, confirming its selectivity for ETB over ETA receptors. It is utilized in studies involving vascular tone, pulmonary circulation, and the role of endothelin receptor subtypes in disease models[1][3].

Other names

4AlaET-1