Joachim Bargon1, Ute Bommerich2, Achim Koch3, Kerstin Mnnemann3, Rahim R. Rizi4, Meike Roth3, Hans Wolfgang Spiess3
1Institute of Physical Chemistry, University of Bonn, Bonn, Germany; 2Leibniz Institute for Neurobiology, Magdeburg, Germany; 3NMR Spectroscopy and Imaging, Max-Planck Institute for Polymers, Mainz, Germany; 4Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA, USA
Investigating the role of neurotransmitters like the derivatives of choline and disorders of their metabolism via 13C-MRS/MRI requires hyperpolarized forms thereof due to the low intrinsic sensitivity of these methods. Parahydrogen Induced Polarization (PHIP) is a suitable method to provide 13C-hyperpolarized targets, but requires suitable unsaturated precursors, which for molecules like choline are difficult to provide. Instead, 13C-hyperpolarized choline, - and likewise lecithin -, can be generated indirectly by parahydrogenating unsaturated forms of succinylcholine or lecithin. The latter can be labeled with 13C and is cleaved by enzymes into the corresponding components. Thereupon choline becomes acetylated to provide hyperpolarized acetylcholine