Manganese(II)-Based Responsive Contrast Agent Detects Glucose-Stimulated Zinc Secretion from the Mouse Pancreas and Prostate by MRI
Sara Chirayil, Veronica Clavijo Jordan, André F. Martins, Namini Paranawithana, S. James Ratnakar, A. Dean Sherry
Abstract
A Mn(II)-based zinc-sensitive MRI contrast agent, MnPyC3A–BPEN, was prepared, characterized, and applied in imaging experiments to detect glucose-stimulated zinc secretion (GSZS) from the mouse pancreas and prostate in vivo. Thermodynamic and kinetic stability tests showed that MnPyC3A–BPEN has superior kinetic inertness compared to GdDTPA, is less susceptible to transmetalation in the presence of excess Zn2+ ions, and less susceptible to transchelation by albumin. In comparison with other gadolinium-based zinc sensors bearing a single zinc binding moiety, MnPyC3A–BPEN appears to be a reliable alternative for imaging β-cell function in the pancreas and glucose-stimulated zinc secretion from the prostate.