Abstract #2430

Imaging Carbonic Anhydrase Activity Using Hyperpolarized 13C-Labeled Bicarbonate

Ferdia Aidan Gallagher^1,2, Mikko I. Kettunen^2,3, Rebekah L. McLaughlin^2,3, De-en Hu^2,3, Tim H. Witney^2,3, Jan H. Ardenkjaer-Larsen⁴, Kevin M. Brindle^2,3

¹Radiology, University of Cambridge, Cambridge, UK; ²CRUK Cambridge Research Institute, Cambridge, UK; ³Biochemistry, University of Cambridge, Cambridge, UK; ⁴GE Healthcare, Amersham, UK

Carbonic anhydrase (CA) is of biological importance because tumor-associated CAs (e.g. CA IX) have been shown to be strongly induced by hypoxia and controlled by hypoxia-inducible factor-1 (HIF-1). Therefore imaging CA may directly relate to hypoxia and HIF-1 activation. We show here that CA activity can he imaged both in vitro and in vivo following the injection of hyperpolarized ¹³C-labeled bicarbonate by saturating the ¹³C-labeled carbon dioxide. This represents a new application of Dynamic Nuclear Polarization.