Continuous Infusion of 20-Hydroxyecdysone Increased Mass of Triceps Brachii in C57BL/6 Mice
Diana M. Cheng       Phytotherapy Research   Early View (Online Version of Record published before inclusion in an issue)

Phytoecdysteroids have been attributed with numerous pharmacological properties in animals, including increasing muscle mass, and 20-hydroxyecdysone (20E) is one of the most abundant phytoecdysteroids produced by plants. In this study, the physiological and gene expression effects of 20E were analyzed in C57BL/6 mice given a continuous infusion of saline or 20E (5 mg/kg/day) for 5 or 15 days using subcutaneously implanted Alzet® osmotic pumps. The masses of the total body, muscle groups and organs were determined. There was a significant increase ( p = 0.01) in the mass of triceps brachii in mice treated with 20E for 5 days (115 ± 8 mg) compared with mice treated with saline for 5 days (88 ± 3 mg), however, there were no differences in the other measured parameters. To determine potential mechanisms of 20E in skeletal muscle, Illumina’s Mouse Whole Genome-6 v2.0 Expression BeadChips were used to evaluate changes in gene expression of the triceps brachii after 20E infusion. Ingenuity Pathways Analysis was used to identify genes with the most evidence for differential expression, of which, 16 genes involved in the skeletal and muscular system were identified. Overall, the data suggest that 20E does not have potent anabolic properties, however, a muscle-specific increase was observed and genes were identified to provide an explanation for the muscle accretion.

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Effects of a hypercaloric diet on β-cell responsivity in lean healthy men
Myrte Brands   Clinical Endocrinology

Objective
Insulin resistance and hyperinsulinemia precede the onset of obesity-induced DM2. The early adaptation of the β-cell during the initial phase of overfeeding and weight gain has only been partly elucidated. We studied the early changes in insulin clearance and β-cell responsivity during a positive and negative energy balance in lean healthy subjects.
Design
We studied in 9 healthy lean men (age 37 [27-43] years and BMI 23.6 [20.6-25.6] kg/m2), insulin sensitivity, insulin clearance, insulin secretion and static and dynamic β-cell responsivity at baseline and after the hypercaloric and subsequent hypocaloric diet.

Results
Participants gained 7 [5.1-7.6]% of their initial body weight on the hypercaloric diet. Compared to baseline, insulin sensitivity and insulin clearance decreased, while glucose-stimulated insulin secretion was higher. The GLP-1 response to oral glucose did not change. The dynamic β-cell responsivity index increased but the basal and static responsivity indices did not change. Total and static disposition indexes in the hypercaloric state showed a trend towards a decrease.

During the hypocaloric diet, insulin sensitivity, glucose-stimulated insulin secretion and insulin clearance returned to baseline. The responsivity and the disposition indexes were not different in the hypocaloric phase compared to baseline.

Conclusion
A positive energy balance resulting in weight gain in lean men induces hyperinsulinemia, which is explained by a combined effect on insulin clearance and insulin secretion. Increased insulin secretion was related to insulin resistance-induced higher glucose concentrations but also to increased dynamic β cell responsivity. Glucose sensitivity of the β-cell did not change. These early adaptations are completely reversible during a negative energy balance after loss of the gained weight.

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Pour tous les crétins qui pensent que je ne réponds pas aux questions, cette étude illustre bien le fait qu’un ou un non est une mauvaise réponse
After caffeine ingestion, 11 subjects performed more repetitions, 14 performed fewer repetitions, and 4 performed the same number of repetitions.

No Effects of Caffeine on Muscle Hypertrophy-Style Resistance Exercise
Marius Steiro Fimland and Atle Hole Saeterbakken
Journal of Caffeine Research. June 2011, 1(2): 117-121.

Objective: The purpose of this study was to investigate effects of prior caffeine ingestion on repetitions performed during muscle hypertrophy-style bench press in men and women.

Methods: In a counterbalanced, placebo-controlled, cross-over design, 29 resistance trained men (n=19) and women (n=10) ingested either caffeine (6 mg/kg) or identical placebo pills 1 hour before two experimental sessions. A separate familiarization and one repetition maximum (1-RM) testing session was performed. The experimental sessions consisted of warm-up and six sets of bench press with 70% of 1-RM. Each set was performed until volitional failure and separated by 2-minute rest periods. Repetitions were performed at a constant pace (2 seconds eccentric and 2 seconds concentric).

Results: No effects of caffeine were observed. The total number of repetitions during 6 consecutive sets for men in the caffeine trial was 44±6, and in the placebo trial 44±7. Women performed 51±15 repetitions in the caffeine trial, and 52±19 repetitions in the placebo trial. Men and women combined performed on average 46±10 repetitions in the caffeine trial, and 47±13 repetitions in the placebo trial. After caffeine ingestion, 11 subjects performed more repetitions, 14 performed fewer repetitions, and 4 performed the same number of repetitions.

Conclusions: This study suggests that resistance trained men and women do not benefit from caffeine supplementation before muscle hypertrophy-style bench press.

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Effet de l’huile fixe de la nigelle (Nigella sativa L.) sur le profil des androgènes chez le rat male
  Phytothérapie Volume 9, Number 6, 338-342,
M. El Khasmi, A. Issaoub Allah, M. Farh, F. Riad, A. Safwate, N. El Abbadi and E. H. Tahri

Les extraits des graines de la nigelle sont largement utilisés dans la médecine traditionnelle. Nous avons étudié l’effet de l’huile fixe de la nigelle sur les taux plasmatiques de la testostérone (T), de l’hormone folliculostimulante (FSH), de l’hormone lutéinisante (LH) et sur le poids corporel et celui des organes reproducteurs chez le rat. Vingt rats mâles ont été divisés en deux groupes de dix: le groupe témoin et celui traité avec l’huile de la nigelle (0,5 ml/kg) par voie intrapéritonéale pendant 30 jours. Nos résultats ont montré que l’huile de la nigelle augmente significativement la masse des organes reproducteurs et les concentrations plasmatiques de la T, de la FSH et de la LH comparativement aux animaux témoins (p < 0,05). L’induction de la stéroïdogenèse observée pourrait être médiée par une activation de l’axe hypothalamohypophysogonadique.

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Association between plasma 25-OH vitamin D and testosterone levels in men
Katharina Nimptsch                 Clinical Endocrinology

Objective:  A small randomized controlled trial suggested that vitamin D might increase the production of testosterone in men, which is supported by experimental studies in animals and a cross-sectional study showing positive associations between plasma 25-hydroxyvitamin D [25(OH)D] and testosterone and concordant seasonal variation of both biomarkers.

Design and Measurements:  We investigated the cross-sectional association of plasma 25(OH)D levels and total and free testosterone measured by immunoassay in 1,362 male participants of the Health Professionals Follow-up Study who were selected for a nested case-control study on prostate cancer using multivariate adjusted linear and restricted cubic spline regression models.

Results:  25(OH)D was positively associated with total and free testosterone levels. From the lowest to the highest 25(OH)D quintile, multivariate adjusted means (95% confidence interval) were 18.5 (17.7; 19.4), 19.4 (18.6; 20.2), 19.6 (18.8; 20.4), 20.1 (19.3; 20.9) and 20.0 (19.1; 20.8); p-trend=0.003) for total testosterone and 97.7 (93.9; 101.5), 98.2 (94.1; 102.2), 99.2 (95.2; 103.2), 100.7 (96.9; 104.5) and 101.5 (97.6; 105.4; p-trend=0.03) for free testosterone. The shapes of the dose-response curves indicate that the association between 25(OH)D and total and free testosterone is linear at lower levels of 25(OH)D (below approximately 75-85 nmol/l), reaching a plateau at higher levels. Unlike for 25(OH)D, we did not observe any seasonal variation of testosterone concentrations.

Conclusion:  This study supports previously reported positive associations between vitamin D and testosterone although we did not observe parallel seasonal variation patterns. Possible causality and direction of the vitamin D-testosterone association deserve further scientific investigation.

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http://www.stripes.com/news/aafes-pulls-weight-loss-bodybuilding-supplement-from-shelves-1.162471

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Exploration détaillée des composantes de la glycorégulation chez des sportifs sujets aux hypoglycémies d’effort. Intérêt de l’oral minimal model
J.-F. Brun   Science & Sports Volume 26, Issue 5, November 2011, Pages 286-291

Les hypoglycémies à l’exercice (HE) sont une situation très fréquente mais peu étudiée. Elles surviennent chez des sujets présentant des valeurs élevées d’insulino-sensibilité (SI) et d’efficience glucidique (SG). SI et SG peuvent être calculées à partir de repas-tests par une modélisation mathématique qui permet aussi une étude approfondie des composantes de la sécrétion d’insuline.

Méthodes et résultats
Nous avons étudié les résultats fournis par cette méthode chez 19 sportifs se plaignant d’HE comparés à 58 sportifs appariés ne présentant pas ce problème. On observe des valeurs plus élevées de SI (p < 0,05) et SG (p

Conclusion
Ainsi, ces sujets ont une assimilation glucidique massive, leur sécrétion d’insuline se réduisant de façon compensatoire mais cette réduction a des limites et peut s’avérer insuffisante, notamment en ce qui concerne la sensibilité β-pancréatique au glucose.

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