This is a single-blind, randomized placebo-controlled, parallel study, where the study volunteers will be blinded to testosterone/placebo treatment. This study will test a relatively new, less invasive method for collecting muscle tissue to determine if this method is appropriate for collecting muscle samples for the assessment of the fractional synthetic rates (FSR) of muscle-derived proteins. This study will also investigate whether the FSR of proteins may serve as early biomarkers for muscle anabolism, a known anabolic agent (testosterone) will be administered to healthy, elderly male subjects over a 3 week period. The fractional synthetic rate of several muscle-derived proteins will be analyzed at Baseline and during the period of testosterone treatment using deuterium labelling of these proteins by the incorporation of deuterium from deuterated water (D2O).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
DIAGNOSTIC
Masking
SINGLE
Enrollment
20
D2O 70% will be supplied as clear liquid, provided in 50 millilitre (mL) unit dose vials; administered per orally.
Testosterone enanthate 125mg injection will be supplied as colorless to pale yellow liquid; administered intramuscular (IM).
Placebo to match testosterone enanthate 0.625 mL injection will be supplied as greenish yellow, bright and clear oily liquid; administered intramuscular (IM).
GSK Investigational Site
Durham, North Carolina, United States
Change from Baseline in muscle derived protein synthesis rate
Muscle protein synthesis will be assessed by measuring the fractional synthetic rate of muscle-derived proteins in both muscle biopsy samples and in blood after subjects have ingested deuterated water. The FSR of several muscle-derived proteins will be analyzed at baseline and during the period of testosterone treatment using deuterium labelling of these proteins by the incorporation of deuterium from D2O.
Time frame: Baseline and Day 21
Change from Baseline in lower extremity strength using the 1-repetition maximum (1-RM) leg strength, FSRs from muscle proteins derived from muscle biopsies and serum samples
Lower extremity strength will be measured as the 1-RM on a leg press device. Strength will be measured at baseline (Day 1, prior to start of testosterone) and at study end (Day 21). The FSR of several muscle-derived proteins will be analyzed at Baseline and during the period in both muscle biopsy samples and in blood after subjects have ingested deuterated water.
Time frame: Baseline, Day 7, 14, and 21
Changes in FSR in muscle and serum derived muscle proteins
The FSR of several muscle-derived proteins will be analyzed at Baseline and during the period in both muscle biopsy samples and in blood after subjects have ingested deuterated water.
Time frame: Baseline, Day 7, 14, and 21
Number of biopsy samples required to obtain desired collection weight
Time frame: Baseline, Day 7, 14, and 21
Number of participants with biopsy-related adverse events
Time frame: Upto Week 7
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.