David L Chinkes1. 1. Department of Surgery, University of Texas Medical Branch and Shriners Hospitals for Children, Galveston, Texas 77550, USA. dlchinke@utmb.edu
Abstract
PURPOSE OF REVIEW: To describe the latest innovations in measuring protein breakdown in vivo, particularly in muscle. RECENT FINDINGS: The traditional method of using 3-methylhistidine excretion to measure muscle protein breakdown has been updated to include arteriovenous or microdialysis measurements, which address the concern that there are alternative sources of 3-methylhistidine in the body other than muscle. Several variations of a precursor-product method to measure fractional breakdown rate of tissues have been developed that are analogous to fractional synthesis rate of tissues. These methods are more generally applicable than the 3-methylhistidine methods and are less invasive than arteriovenous methods. The various precursor-product methods are distinguished by whether they require an isotopic steady state or multiple tracers and by how many biopsies are required. SUMMARY: The new precursor-product methods have enabled assessment in clinical trials of protein breakdown for proteins other than myofibrillar proteins and in circumstances in which arteriovenous sampling is not feasible.
PURPOSE OF REVIEW: To describe the latest innovations in measuring protein breakdown in vivo, particularly in muscle. RECENT FINDINGS: The traditional method of using 3-methylhistidine excretion to measure muscle protein breakdown has been updated to include arteriovenous or microdialysis measurements, which address the concern that there are alternative sources of 3-methylhistidine in the body other than muscle. Several variations of a precursor-product method to measure fractional breakdown rate of tissues have been developed that are analogous to fractional synthesis rate of tissues. These methods are more generally applicable than the 3-methylhistidine methods and are less invasive than arteriovenous methods. The various precursor-product methods are distinguished by whether they require an isotopic steady state or multiple tracers and by how many biopsies are required. SUMMARY: The new precursor-product methods have enabled assessment in clinical trials of protein breakdown for proteins other than myofibrillar proteins and in circumstances in which arteriovenous sampling is not feasible.
Authors: Demidmaa Tuvdendorj; David L Chinkes; David N Herndon; Xiao-Jun Zhang; Robert R Wolfe Journal: Am J Physiol Endocrinol Metab Date: 2013-01-15 Impact factor: 4.310
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Authors: Lars Holm; Kasper Dideriksen; Rie H Nielsen; Simon Doessing; Rasmus L Bechshoeft; Grith Højfeldt; Marcus Moberg; Eva Blomstrand; Søren Reitelseder; Gerrit van Hall Journal: Physiol Rep Date: 2019-09