Journal ArticleDOI
Androgen receptor antagonist suppresses exercise-induced hypertrophy of skeletal muscle.
TLDR
The result suggests that the androgen pathway has a significant effect in exercise-induced muscle hypertrophy and emphasizes the importance of the increase in the number of androgen receptors in exercised muscle.Abstract:
The physiological importance of the increase in androgen receptors in exercise-induced muscle hypertrophy was investigated in rats. Together with training rat gastrocnemius muscles by electrical stimulation every other day for 2 weeks, male rats were administered the androgen receptor antagonist, oxendolone. The androgen receptor antagonist effectively decreased the wet mass of the prostate, an androgen target organ, and did not significantly affect body mass. The increase in muscle mass induced by electrical stimulation was effectively suppressed by the androgen receptor blockade. The mean degree of muscle hypertrophy in the antagonist-treated group was significantly lower than that in the control group (102.30% vs 107.41%, respectively;P=0.006). This result suggests that the androgen pathway has a significant effect in exercise-induced muscle hypertrophy and emphasizes the importance of the increase in the number of androgen receptors in exercised muscle.read more
Citations
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Journal ArticleDOI
Hormonal Responses and Adaptations to Resistance Exercise and Training
TL;DR: It appears that this acute response to resistance exercise is more critical to tissue growth and remodelling than chronic changes in resting hormonal concentrations, as many studies have not shown a significant change during resistance training despite increases in muscle strength and hypertrophy.
Journal ArticleDOI
Blood Hormones as Markers of Training Stress and Overtraining
TL;DR: An intraindividually decreased maximum rise of pituitary hormones (corticotrophin, growth hormone, cortisol and insulin has been found after a standardised exhaustive exercise test performed with an intensity of 10% above the individual anaerobic threshold, suggesting an impaired hypothalamic regulation.
Journal ArticleDOI
Anabolic androgenic steroids: a survey of 500 users.
TL;DR: AAS users in this sample are taking larger doses than previously recorded, with more than half of the respondents using a weekly AAS dose in excess of 1000 mg, and several trends in the nonmedical use of AAS are revealed.
Journal ArticleDOI
Testosterone physiology in resistance exercise and training: the up-stream regulatory elements.
Jakob L. Vingren,William J. Kraemer,Nicholas A. Ratamess,Jeffrey M. Anderson,Jeff S. Volek,Carl M. Maresh +5 more
TL;DR: Testosterone is an important modulator of muscle mass in both men and women and acute increases in testosterone can be induced by resistance exercise, and the variables within the acute programme variable domains must be selected such that the resistance exercise session contains high volume and metabolic demand to induce an acute testosterone response.
Journal ArticleDOI
Current Concepts in Anabolic-Androgenic Steroids
TL;DR: Clinical studies have discovered novel therapeutic uses for physiologic doses of AAS, without any significant adverse effects in the short term, and guidelines for the clinical evaluation of Aas users will be presented for sports medicine practitioners.
References
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Journal ArticleDOI
Steroid structure and androgenic activity. Specificities involved in the receptor binding and nuclear retention of various androgens
TL;DR: It is found that many potent synthetic androgens can bind directly to β protein and to prostate cell nuclei without a metabolic conversion, indicating that the bulkiness and flatness of the steroid molecule play a more important role in receptor binding than the detailed electronic structure at the Δ4 bond of Ring A.
Journal ArticleDOI
Immunohistochemical localization of androgen receptors with mono- and polyclonal antibodies to androgen receptor.
TL;DR: The monoclonal antibody could also demonstrate androgen receptor-positive cells in a human prostatic cancer and in a prostate with benign hyperplasia, demonstrating the use of antibodies in revealing cellular/subcellular distribution of androgen receptors in target tissues.
Journal ArticleDOI
Insulin-like growth factors (IGF) in muscle development. Expression of IGF-I, the IGF-I receptor, and an IGF binding protein during myoblast differentiation.
TL;DR: It is demonstrated that several components critical to IGF action are produced in a fusing skeletal muscle cell line in a differentiation-dependent manner and suggest that both IGF-I and IGF-II may be autocrine factors for muscle.
Journal ArticleDOI
Relative Binding Affinity of Anabolic-Androgenic Steroids: Comparison of the Binding to the Androgen Receptors in Skeletal Muscle and in Prostate, as well as to Sex Hormone-Binding Globulin
TL;DR: When several anabolic steroids were tested as competitors for the binding of [3H]methyltrienolone (MT; 17 beta-hydroxy-17 alpha-methyl-4,9,11-estratrien-3-one) to the AR in rat and rabbit skeletal muscle and rat prostate, respectively, MT itself was the most efficient competitor.
Journal ArticleDOI
Regulation of Androgen Receptor Protein and mRNA Concentrations by Androgens in Rat Ventral Prostate and Seminal Vesicles and in Human Hepatoma Cells
TL;DR: Immunohistochemical studies showed that AR is a nuclear protein of the prostatic epithelial cells in both intact and castrated rats, and suggested that short term castration increases the concentration of nuclear AR in the prostate.
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