In vivo 13C spectroscopy in the rat brain using hyperpolarized [1-13C]pyruvate and [2-13C]pyruvate

The low sensitivity of C-13 spectroscopy can be enhanced using dynamic nuclear polarization. Detection of hyperpolarized [1-C-13]pyruvate and its metabolic products has been reported in kidney, liver, and muscle. In this work, the feasibility of measuring C-13 signals of hyperpolarized C-13 metabolic products in the rat brain in vivo following the injection of hyperpolarized [1-C-13]pyruvate and [2-C-13]pyruvate is investigated. Injection of [2-C-13]pyruvate led to the detection of [2-C-13]lactate, but no other downstream metabolites such as TCA cycle intermediates were detected. Injection of [1-C-13]pyruvate enabled the detection of both [1-C-13]lactate and [C-13]bicarbonate. A metabolic model was used to fit the hyperpolarized C-13 time courses obtained during infusion of [1-C-13]pyruvate and to determine the values of V-PDH and V-LDH. (C) 2010 Elsevier Inc. All rights reserved.