Endothelin stimulates both cAMP formation and phosphatidylinositol hydrolysis in cultured embryonic bovine tracheal cells

Abstract
Embryonic bovine tracheal (EBTr) cells were found to possess receptors for endothelin (ET) of ET‐1‐selective (ETA)subtype with a K d for ET‐1 of 114 pM and a B max of 12.9 fmol/105 cells. Stimulation of EBTr cells with 100 pM to 100 nM ET‐1 increased the contents of both inositol phosphates and cAMP in a concentration‐dependent manner, indicating that the receptors are coupled to both phosphatidylinositol hydrolysis and cAMP formation in EBTr cells.