The end-product method of measuring whole-body protein turnover: a review of published results and a comparison with those obtained by leucine infusion.
The present review summarizes the results of all published papers on whole-body protein turnover in man measured by [15N]glycine and the end-product method using both urea and ammonia. It begins with a short account of the underlying assumptions and the justification for the use of [15N]glycine. The results are then compared with those of a large sample of measurements by the 'gold standard' precursor method with continuous infusion of [13C]leucine. The pros and cons of the two methods are compared and it is suggested that there is a place for further work by the less invasive end-product method, particularly for population studies of the genetic, environmental and functional determinants of whole-body rates of protein synthesis.
Duggleby
S L
SL
MRC Epidemiology Resource Centre, Southampton General Hospital, Southampton 5022 5A, UK.
Waterlow
J C
JC
D000284:Administration, Oral; D000641:Ammonia / Q000378:metabolism; D004334:Drug Administration Schedule; D005260:Female; D005998:Glycine / Q000378:metabolism*; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D007930:Leucine / Q000008:administration & dosage*; D008297:Male; D009587:Nitrogen Isotopes / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D011849:Radioactive Tracers; D014508:Urea / Q000378:metabolism; D014915:Whole-Body Counting / Q000379:methods
D009587:Nitrogen Isotopes; D011506:Proteins; D011849:Radioactive Tracers; D000641:Ammonia; D014508:Urea; D007930:Leucine; D005998:Glycine