Xiao-Hong Zhu1, Yi Zhang1, Kamil Ugurbil1, Wei Chen1
1CMRR, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA
Adenosine triphosphate (ATP) metabolism provides energy at cellular level for all living species. In the brain, majority of ATP is formed in mitochondria through oxidative phosphorylation and utilized in cytosol for supporting normal brain function. By applying the in vivo 31P MRS in combine with the magnetization transfer (MT) approach, we are able to directly and non-invasively measure the cerebral metabolic rate of ATP (CMRATP) in cat brain at 9.4T. The results of the CMRATP measurement have been validated via: i) using different MT techniques; and ii) comparing with the estimated CMRATP derived from the CMRO2 previously obtained from the same cat model. In addition, by correlating the experimentally determined CMRATP with the CMRO2 values in cat, as well as in rat and human brain, we could obtain the P:O ratios in these species, which indicate that oxidative phosphorylation indeed dominates the ATP production in these resting brains.