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Simple measurement of gluconeogenesis by direct 2 H NMR analysis of menthol glucuronide enrichment from 2 H 2 O

2005; Wiley; Volume: 54; Issue: 2 Linguagem: Inglês

10.1002/mrm.20567

1522-2594

A. Pedro Ribeiro, M. Madalena Caldeira, Manuela Carvalheiro, Margarida Bastos, Carla Baptista, Ana Fagulha, Luísa Barros, Cristina Barosa, John G. Jones,

Parkinson's Disease Mechanisms and Treatments

Abstract The contribution of gluconeogenesis to fasting glucose production was determined by a simple measurement of urinary menthol glucuronide (MG) 2 H enrichment from 2 H 2 O. Following ingestion of 2 H 2 O (0.5% body water) during an overnight fast and a pharmacological dose (400 mg) of a commercial peppermint oil preparation the next morning, 364 μmol MG was quantitatively recovered from a 2‐h urine collection by ether extraction and a 125 μmol portion was directly analyzed by 2 H NMR. The glucuronide 2 H‐signals were fully resolved and their relative intensities matched those of the monoacetone glucose derivative. The pharmacokinetics and yields of urinary MG after ingestion of 400 mg peppermint oil as either gelatin or enteric‐coated capsules 1 h before breakfast were quantified in five healthy subjects. Gelatin capsules yielded 197 ± 81 μmol of MG from the initial 2‐h urine collection while enteric‐coated capsules gave 238 ± 84 μmol MG from the 2‐ to 4‐h urine collection. Magn Reson Med 54:429–434, 2005. © 2005 Wiley‐Liss, Inc.