| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
SKELETAL MUSCLE AND EXERCISE |
1 Institute of Sport Science and Clinical Biomechanics, University of Southern Denmark, Denmark
2 Department of Endocrinology, Odense University Hospital, Denmark
3 Department of Molecular Muscle Biology, CMRC, Rigshospitalet, Denmark
4 Department of Medical Biochemistry and Genetics, University of Copenhagen, Denmark
5 Institute of Sports Medicine, Copenhagen, Bispebjerg University Hospital, Denmark
We hypothesized that suppression of endogenous testosterone blunts mRNA expression post strength training (ST). Twenty-two young men were randomized for treatment with the GnRH analogue goserelin (3.6 mg every 4 weeks) or placebo for a period of 12 weeks. The ST period of 8 weeks started at week 4. Strength test, blood sampling, muscle biopsies, and whole-body dual-energy X-ray absorptiometry (DXA) scan were performed at weeks 4 and 12. Muscle biopsies were taken during the final ST session (pre, post 4 h, and post 24 h). Resting serum testosterone decreased significantly (P < 0.01) in the goserelin group from 22.6 ± 1.6 (mean ± S.E.M.) to 2.0 ± 0.1 nmol l–1 (week 4), whereas it remained unchanged in the placebo group. An acute increase of serum testosterone was observed during the final ST session in the placebo group (P < 0.05), whereas a decreased response was observed in the goserelin group (P < 0.05). mRNA expression of IGF-IE(bc) and myogenin increased, while expression of myostatin decreased (P < 0.01); however, no differences were observed between the groups. Muscle strength and muscle mass showed a tendency to increase more in the placebo group than in the goserelin group (P = 0.05). In conclusion, despite blocked acute responses of testosterone and 10- to 20-fold lower resting levels in the goserelin group, ST resulted in a similar mRNA expression of myoD, myogenin, IGF-IE(abc), myostatin and androgen receptor as observed in the placebo group. Therefore, in the present study, the molecular events were the same, despite divergent muscle hypertrophy and strength gains.
(Received 11 October 2006;
accepted after revision 2 November 2006;
first published online 9 November 2006)
Corresponding author T. Kvorning: Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark. Email: tkvorning{at}health.sdu.dk
This article has been cited by other articles:
|
|
 |
|
  M. I. Lewis, M. Fournier, T. W. Storer, S. Bhasin, J. Porszasz, S.-G. Ren, X. Da, and R. Casaburi Skeletal muscle adaptations to testosterone and resistance training in men with COPD J Appl Physiol, October 1, 2007; 103(4): 1299 - 1310. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. D. R. Harridge Plasticity of human skeletal muscle: gene expression to in vivo function Exp Physiol, September 1, 2007; 92(5): 783 - 797. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
