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 (ET A )subtype with a K d for ET-1 of 114 pM and a B max of 12.9 fmol/10 5 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.