Daniel M. Spielman1, Dirk Mayer1,2, Yi-Fen Yen3, James Tropp4, Ralph E. Hurd3, Adolf Pfefferbaum2,5
1Radiology, Stanford University, Stanford, CA, USA; 2SRI International, Menlo Park, CA, USA; 3GE Healthcare, Menlo Park, CA, USA; 4GE Healthcare, Fremont, CA, USA; 5Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
Using in vivo 13C-MRS of hyperpolarized pyruvate, we report a two-fold increased rate of rat liver pyruvate-to-lactate conversion in the presence of ethanol, an effect attributable to elevated levels of nicotinamide adenine dinucleotide (NADH) associated with ethanol metabolism in combination with NADHs role as a coenzyme in pyruvate-to-lactate conversion. In addition to providing a tool to investigate pathologies including alcoholic fatty liver disease and cirrhosis, these results, viewed as an indirect assay of changes in NADH levels, indicate hyperpolarized 13C-pyruvate can potentially be useful for interrogating any of the large number of in vivo metabolic pathways involving the coenzyme NAD+/NADH.