title: Determination of steady-state protein breakdown rate in vivo by the disappearance of protein-bound tracer-labeled amino acids: a method applicable in humans.
abstract: A method to determine the rate of protein breakdown in individual proteins was developed and tested in rats and confirmed in humans, using administration of deuterium oxide and incorporation of the deuterium into alanine that was subsequently incorporated into body proteins. Measurement of the fractional breakdown rate of proteins was determined from the rate of disappearance of deuterated alanine from the proteins. The rate of disappearance of deuterated alanine from the proteins was calculated using an exponential decay, giving the fractional breakdown rate (FBR) of the proteins. The applicability of this protein-specific FBR approach is suitable for human in vivo experimentation. The labeling period of deuterium oxide administration is dependent on the turnover rate of the protein of interest.
authors: Institute of Sports Medicine, Department of Orthopedic Surgery M81, Bispebjerg Hospital, and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. L.Holm.isotope@gmail.com
authors: Lars
authors: L
authors: Holm
authors: Bruce
authors: B
authors: O'Rourke
authors: David
authors: D
authors: Ebenstein
authors: Michael J
authors: MJ
authors: Toth
authors: Rasmus
authors: R
authors: Bechshoeft
authors: Niels-Henrik
authors: NH
authors: Holstein-Rathlou
authors: Michael
authors: M
authors: Kjaer
authors: Dwight E
authors: DE
authors: Matthews
mesh_terms: D000409:Alanine / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D001834:Body Water / Q000378:metabolism; D017666:Deuterium Oxide; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D007700:Kinetics; D008297:Male; D008954:Models, Biological; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000596:Amino Acids; D001798:Blood Proteins; D017666:Deuterium Oxide; D000409:Alanine