Venous plasma KIC and muscle protein bound leucine enrichments.

Enrichments in the precursor; venous plasma alpha-13C-ketoisocaproic acid (KIC) in percent tracer-to-tracee ratio (TTR) at time points every hour throughout the FSR-determination period. An effect of time (p13C/12C in leucine liberated from the myofibrillar and sarcoplasmic protein fractions, respectively, in the muscle tissue at 1 and 4 hours at sea level and at altitude. N = 8 and values are mean ± SEM.