Table 2.
Parameter | Placebo (n = 8) | 100 mg Testosterone (n = 6) | 300 mg Testosterone (n = 8) | |||
---|---|---|---|---|---|---|
Baseline | Day 7 | Baseline | Day 7 | Baseline | Day 7 | |
Plasma 13C6-phea | 7.1 ± 0.9 | 7.2 ± 0.7 | 7.0 ± 0.8 | 7.3 ± 0.8 | 7.0 ± 0.6 | 7.2 ± 0.7 |
Muscle Free pool 13C6-pheb | 4.3 ± 0.5 | 4.5 ± 0.8 | 4.0 ± 0.4 | 4.4 ± 0.6 | 4.4 ± 0.2 | 4.5 ± 0.7 |
Mixed muscle protein 13C6-phec | 0.0195 ± 0.0050 | 0.0198 ± 0.0017 | 0.0184 ± 0.0035 | 0.0250 ± 0.0091 | 0.0173 ± 0.0023 | 0.0233 ± 0.0081 |
Mixed muscle protein synthesis rate (% per hour) | 0.050 ± 0.011 | 0.052 ± 0.006 | 0.052 ± 0.010 | 0.063 ± 0.179 | 0.044 ± 0.006 | 0.060 ± 0.026 |
Mean ± SD. Mixed muscle protein synthesis rate calculated using muscle free pool 13C6-phe enrichment to reflect precursor pool enrichment
aAverage plasma TTR measured during 11–12 h of the tracer infusion
bAverage of 3- and 12-h muscle free pool TTR measurements
cMixed muscle protein TTR increment from 3–12 h of the tracer infusion