Estimating Protein Turnover with a [13N,15C]Leucine Tracer: a Study Using Simulated Data

✍ Scribed by Ian J. Gowrie; Abdul V. Roudsari; A.Margot Umpleby; Roman Hovorka

• Book ID: 102610384
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 131 KB
• Volume: 198
• Category: Article
• ISSN: 0022-5193
• DOI: 10.1006/jtbi.1999.0907

✦ Synopsis

We explore the use of [ 15 N, 13 C]leucine tracer to estimate whole-body fractional rates of a fast-turning-over protein pool employing synthetic data. The kinetics of [ 15 N, 13 C]leucine tracer are simplified compared with those of traditional leucine tracers and benefit from irreversible transamination to [ 13 C]a-ketoisocaproaic acid (KIC) resulting in a simplified model structure.

A three-compartment model of [ 15 N, 13 C]leucine kinetics was proposed and evaluated using data generated by a Reference Model (based on a model by Cobelli et al.). The results suggest that fractional turnover rates of a fast-turning-over protein pool can be estimated with low but acceptable precision during a six-hour constant intravenous infusion of [ 15 N, 13 C]leucine with frequent sampling of plasma tracer-to-tracee ratio (TTR) of [ 15 N, 13 C]leucine. We conclude that [ 15 N, 13 C]leucine may be useful for the measurement of protein kinetics and its full potential should be explored in clinical studies with compartmental data analysis.