In:
The Journal of Clinical Endocrinology & Metabolism, The Endocrine Society, Vol. 107, No. 8 ( 2022-07-14), p. e3254-e3263
Kurzfassung:
Effects of testosterone on integrated muscle protein metabolism and muscle mass during energy deficit are undetermined. Objective The objective was to determine the effects of testosterone on mixed-muscle protein synthesis (MPS), proteome-wide fractional synthesis rates (FSR), and skeletal muscle mass during energy deficit. Design This was a randomized, double-blind, placebo-controlled trial. Setting The study was conducted at Pennington Biomedical Research Center. Participants Fifty healthy men. Intervention The study consisted of 14 days of weight maintenance, followed by a 28-day 55% energy deficit with 200 mg testosterone enanthate (TEST, n = 24) or placebo (PLA, n = 26) weekly, and up to 42 days of ad libitum recovery feeding. Main Outcome Measures Mixed-MPS and proteome-wide FSR before (Pre), during (Mid), and after (Post) the energy deficit were determined using heavy water (days 1-42) and muscle biopsies. Muscle mass was determined using the D3-creatine dilution method. Results Mixed-MPS was lower than Pre at Mid and Post (P & lt; 0.0005), with no difference between TEST and PLA. The proportion of individual proteins with numerically higher FSR in TEST than PLA was significant by 2-tailed binomial test at Post (52/67; P & lt; 0.05), but not Mid (32/67; P & gt; 0.05). Muscle mass was unchanged during energy deficit but was greater in TEST than PLA during recovery (P & lt; 0.05). Conclusions The high proportion of individual proteins with greater FSR in TEST than PLA at Post suggests exogenous testosterone exerted a delayed but broad stimulatory effect on synthesis rates across the muscle proteome during energy deficit, resulting in muscle mass accretion during subsequent recovery.
Materialart:
Online-Ressource
ISSN:
0021-972X
,
1945-7197
DOI:
10.1210/clinem/dgac295
Sprache:
Englisch
Verlag:
The Endocrine Society
Publikationsdatum:
2022
ZDB Id:
2026217-6
