title: Structure-related variable responses of calcium sensitive MRI probes.
abstract: A new series of Gd(3+) complexes based on DO3A (GdL(1)-GdL(4)) was synthesized and investigated. They possess side chains with different structures which determine their varying binding properties and response towards endogenous metal ions, measured by changes in the longitudinal relaxivity (r(1)). GdL(4) exhibits the highest selectivity toward Ca(2+) in comparison to the other complexes, with up to a 63% increase of the r(1). GdL(2) and GdL(3) also respond to different Ca(2+) concentration ranges, however with a lower selectivity since the r(1) changes are also observed in the presence of other cations such as Mg(2+), Zn(2+) or Cu(2+). Assessment of the hydration number (q) via luminescence lifetime measurements confirmed that the change in q is responsible for the r(1) response for all the complexes.
authors: Department for Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.
authors: Ilgar
authors: I
authors: Mamedov
authors: Nikos K
authors: NK
authors: Logothetis
authors: Goran
authors: G
authors: Angelovski
mesh_terms: D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D003287:Contrast Media / Q000737:chemistry* / Q000378:metabolism; D005682:Gadolinium / Q000737:chemistry* / Q000378:metabolism; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry* / Q000378:metabolism; D049449:Luminescence; D008279:Magnetic Resonance Imaging
chemical_list: C520644:1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid; D003287:Contrast Media; D006573:Heterocyclic Compounds, 1-Ring; D005682:Gadolinium; D002118:Calcium