Wei Chen1, Chalermchai Khemtong1, Weina Jiang1, Craig R. Malloy1, and A. Dean Sherry1
A large prior literature on inter-conversion of β-hydroxybutyrate (β-HB) and acetoacetate (AcAc) indicates that the process is mitochondrial and the ratio reflects specifically mitochondrial redox state. Therefore the conversion of [1,3-13C]AcAc to [1,3-13C]β-HB is expected to be sensitive to redox. In this study, we explored the utility of using hyperpolarized [1,3-13C]AcAc to study the mitochondrial redox state in perfused rat hearts. Our results show that the production of HP β-HB from HP-AcAc was much higher in ischemic hearts, reflecting the increased concentration of NADH under this reduced state. The redox-dependent conversion between this metabolic pair in mitochondria may lead to the development of an imaging tool for redox imaging of the heart by hyperpolarized 13C MRI.