Document Detail


Heavy resistance exercise training and skeletal muscle androgen receptor expression in younger and older men.
MedLine Citation:
PMID:  21070797     Owner:  NLM     Status:  In-Process    
Abstract/OtherAbstract:
Effects of heavy resistance exercise on serum testosterone and skeletal muscle androgen receptor (AR) concentrations were examined before and after a 21-week resistance training period. Seven healthy untrained young adult men (YT) and ten controls (YC) as well as ten older men (OT) and eight controls (OC) volunteered as subjects. Heavy resistance exercise bouts (5 × 10 RM leg presses) were performed before and after the training period. Muscle biopsies were obtained before and 1h and 48 h after the resistance exercise bouts from m.vastus lateralis (VL) to determine cross-sectional area of muscle fibers (fCSA) and AR mRNA expression and protein concentrations. No changes were observed in YC and OC while resistance training led to significant increases in maximal strength of leg extensors (1 RM), fCSA and lean body mass in YT and OT. Acute increases occurred in serum testosterone concentrations due to resistance exercises but basal testosterone remained unaltered. Mean AR mRNA expression and protein concentration remained unchanged after heavy resistance exercise bouts compared to pre-values. The individual pre- to post-training changes in resting (pre-exercise) AR protein concentration correlated with the changes in fCSA and lean body mass in the combined group of YT and OT. Similarly, it correlated with the changes in 1 RM in YT. Although mean AR expression did not changed due to the resistance exercise training, the present findings suggest that the individual changes of AR protein concentration in skeletal muscle following resistance training may have an impact on training-induced muscular adaptations in both younger and older men.
Authors:
Juha P Ahtiainen; Juha J Hulmi; William J Kraemer; Maarit Lehti; Kai Nyman; Harri Selänne; Markku Alen; Arto Pakarinen; Jyrki Komulainen; Vuokko Kovanen; Antti A Mero; Keijo Häkkinen
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Publication Detail:
Type:  Journal Article     Date:  2010-11-09
Journal Detail:
Title:  Steroids     Volume:  76     ISSN:  1878-5867     ISO Abbreviation:  Steroids     Publication Date:  2011 Jan 
Date Detail:
Created Date:  2010-12-20     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0404536     Medline TA:  Steroids     Country:  United States    
Other Details:
Languages:  eng     Pagination:  183-92     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 Elsevier Inc. All rights reserved.
Affiliation:
Department of Biology of Physical Activity and Neuromuscular Research Center, University of Jyväskylä, Jyväskylä, Finland. juha.ahtiainen@jyu.fi
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