THE STATE oF HoRMONE AcTioN levels were induced in concert with ligand occupa- tion of certain membrane receptors and this second AND MoLECULAR REGULATION messenger (cAMP) was postulated to initiate intra- cellular phosphorylation of unknown targets. At Molecular Endocrinology and Regulation is a this point, the field ofPeptide Hormone Action also burgeoning field, having experienced a remarkable came into being. period of growth since the late 1960s. At that time, These fields developed together for much ofthe there was no field of Hormone Action. The prevail- next decade. Hormone Action...