Intracellular calcium is currently the subject of widespread interest as a second messenger that triggers and regulates cells activation. A series of improved Ca2+ chelating agents which can be used for 19F NMR and fluorescence detection will be synthesized and evaluated for their absorption and emission characteristics as well as their ability to bind Ca2+. The proposed Ca2+ indicators will have improved optical characteristics over currently used quin2, fura-2 and indo-1, which they resemble structurally except for the fluorophore. In addition, the indicator will be fluorine substituted for 19F NMR detection. The chelator can be used to follow changes in intracellular calcium concentration, [Ca2+]i, as a function of time in response to various perturbing influences. With increasing recognition that changes in transmembrane calcium fluxes and intracellular calcium levels are important in many forms of stimulus- response coupling, the introduction of a Ca2+ specific agent that can be used with both fluorometric and 19F NMR detection promises to provide additional opportunities for the study of cell function. It can be used for single cell imaging, flow cytometry, cell function studies and for NRM study of perfused organs.
