Weight gain increases human aromatase expression in mammary gland
Dong Chen, Hong Zhao, John S. Coon V, Masanori Ono, Elizabeth K. Pearson, Serdar E. Bulun

Molecular and Cellular Endocrinology Volume 355, Issue 1, 15 May 2012, Pages 114–120

Adulthood weight gain predicts estrogen receptor-positive breast cancer. Because local estrogen excess in the breast likely contributes to cancer development, and aromatase is the key enzyme in estrogen biosynthesis, we investigated the role of local aromatase expression in weight gain-associated breast cancer risk in a humanized aromatase (Aromhum) mouse model containing the coding region and the 5′-regulatory region of the human aromatase gene. Compared with littermates on normal chow, female Aromhum mice on a high fat diet gained more weight, and had a larger mammary gland mass with elevated total human aromatase mRNA levels via promoters I.4 and II associated with increased levels of their regulators TNFα and C/EBPβ. There was no difference in total human aromatase mRNA levels in gonadal white adipose tissue. Our data suggest that diet-induced weight gain preferentially stimulates local aromatase expression in the breast, which may lead to local estrogen excess and breast cancer risk.

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Voici un lien pour plus de recherches gratuites sur les gynéco afin d’approfondir le sujet
Gynéco

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Des-acyl ghrelin exhibits pro-anabolic and anti-catabolic effects on C2C12 myotubes exposed to cytokines and reduces burn-induced muscle proteolysis in rats
Sulaiman Sheriff       Molecular and Cellular Endocrinology   Volume 351, Issue 2, 4 April 2012, Pages 286–295

Although ghrelin and GHRP-2 have been shown to inhibit skeletal muscle proteolysis in rats with burn injury, the effects of des-acyl ghrelin (DAG) have not been reported. In this paper, we demonstrate that continuous 24 h administration of DAG attenuated burn-induced EDL muscle proteolysis, and normalized elevated TNFα mRNA. Combined treatment of cultured C2C12 myotubes with TNFα and IFN-γ (TNF + IFN) inhibited protein synthesis and increased protein breakdown; DAG abolished both effects. PI3 kinase inhibition by LY294002 and mTOR inhibition by rapamycin blocked the reversal of the anti-anabolic effects of TNF + IFN-treated myotubes by DAG. DAG also reversed or attenuated the TNF + IFN-induced reduction in phosphorylation of Akt, FOXO1, 4E-BP-1, and GSK-3β in myotubes. Furthermore, DAG attenuated the atrophy signal, phospho-NF-κB, and the mRNA expression of MAFbx and MuRF1, upregulated by TNF + IFN in C2C12 myotubes. We conclude that DAG reduces muscle cachexia produced by injury and proinflammatory cytokines, and that DAG or DAG-based compounds may be useful in treating wasting disorders.

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

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Comparison of Urine Toxic Metals Concentrations between Athletes and Sedentary Subjects
Medicine & Science in Sports & Exercise: May 2011 - Volume 43 - Issue 5 - p 706

Muñoz, Diego1; Llerena, Francisco2; Barrientos, Gema1; Palomo, Rosario3; Pinilla, Eduardo3; Olcina, Guillermo1; Maynar, Marcos1; Caballero, Maria Jesús2

Information about levels of many trace elements in biological tissues is scarce. Toxic trace elements are pervasive in the human environment and are known to accumulate in the human body over lifetime. Studies in athletes during training periods compared to non-training control subjects, indicate increased loses of minerals by sweat and urine.
PURPOSE: The aim of this study was to compare the level of toxic trace elements: lead (Pb), cadmium (Cd), beryllium (Be), tellurium (Te) and tungsten (W) in urine samples between athletes and age-matched sedentary subjects living in the same geographical area.
METHODS: twenty-one middle-distance runners (age 21.6 ± 4.3 years; Body Mass Index (BMI): 18.25 ± 1.73) and twenty-six sedentary men (age 22.65 ± 3.6 years; BMI 21.81±3.14) participated in this study. Morning midstream urine samples were collected in 30 ml polyethylene containers cleaned with 5% (v/v) HNO3 and were transported to the laboratory. The samples were acidified with 1% (v/v) HNO3 and then were vigorously shaken for 1 min prior to their storage at -20ºC. Be, Cd, Pb, Re, Te, and W were determined in urine samples using a Perkin-Elmer Elan 9000 inductively coupled plasma mass spectrometry (ICP-MS) with a quadrupole based collision/reaction cell. Creatinine concentrations were measured in all urine samples to take into account the different degree of dilution. The Mann-Whitney test was performed for statistical analysis. A p value of <0.05 was used to determine statistical significance.
RESULTS: Concentrations, expressed in µg/mg creatinine, of 5 toxic elements in urine from athletes versus sedentary subjects were as follows: Pb (0.938 ± 0.664 vs. 2.162 ± 1.444 p<0.001); Cd (0.123 ± 0.075 vs. 0.069 ± 0.041, p<0.05); Be (0.536 ± 0.244 vs. 0.066 ± 0.035, p<0.001); Te (0.244 ± 0.193 vs. 0.066 ± 0.045, p<0.001); W (0.082 ± 0.053 vs. 0.022 ± 0.006, p<0.001).
CONCLUSION: With the exception of Pb, urine toxic metal concentrations from athletes were higher than from sedentary subjects. This fact suggests that physical activity counteracts, at least in part, the cumulative effect of toxic environment by increasing the urine excretion of toxic metals in trained people.

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