In vivo monitoring of hepatic glutathione in anesthetized rats by13C NMR

Autor: Thomas L. James, Jeffrey M. Macdonald, Olga Schmidlin
Rok vydání: 2002
Předmět:
Zdroj: Magnetic Resonance in Medicine. 48:430-439
ISSN: 1522-2594
0740-3194
DOI: 10.1002/mrm.10244
Popis: A method for in vivo 13C NMR monitoring of hepatic glutathione (GSH) in intact, anesthetized rats has been developed. Studies were conducted using a triple-tuned, surgically implanted surface coil designed for this animal model. The coil permitted complete decoupling and sufficient resolution in the 13C NMR spectrum to monitor the time course of hepatic 13C-metabolites of intravenously administered 2-13C-glycine, particularly GSH at 44.2 ppm and serine signals at 61.1 and 57.2 ppm, respectively. It further allowed concomitant monitoring of high-energy phosphagens and intracellular pH by 31P NMR. To confirm in vivo NMR peak assignments, we compared high-resolution 2D 1H{13C} heteronuclear multiple quantum coherence and 1D 13C spectra of hepatic perchloric acid extracts to those of authentic standards. The fractional isotopic enrichment of hepatic 13C-glycine increased exponentially at a rate of 1.68 h−1 and reached its plateau level of 81% in 2 h. The 13C fractional isotopic enrichment of GSH increased exponentially at a rate of 0.316 h−1 and reached 55% after 4 h of 2-13C-glycine infusion, but without achieving a plateau. To confirm that the resonance at 44.2 ppm resulted from GSH, a rat was given an intravenous dose of 2-oxothiazolidine-4-carboxylic acid (OTC), a cysteine precursor that increases intracellular GSH. As expected, with OTC administration the hepatic 13C GSH-to-glycine peak area increased more than sevenfold. Magn Reson Med 48:430–439, 2002. © 2002 Wiley-Liss, Inc.
Databáze: OpenAIRE
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