This invention relates, e.g., to methods for inhibiting or stimulating an activity of an adrenomedullin (AM) or gastrin releasing peptide (GRP) peptide hormone, comprising contacting the peptide with a small molecule, non-peptide, modulatory agent of the invention. Complexes of these modulatory agents with other components, such as the peptides or blocking antibodies specific for the peptides, are also described, as are pharmaceutical compositions comprising the modulatory agents, and methods for using the modulatory agents to diagnose or treat patients.