ObjectiveOne of the major side effects of glucocorticoid (GC) treatment is lean tissue wasting, indicating a prominent role in systemic amino acid metabolism. In order to uncover a novel aspect of GCs and their intracellular-receptor, the glucocorticoid receptor (GR), on metabolic control, we conducted amino acid and acylcarnitine profiling in human and mouse models of GC/GR gain- and loss-of-function.MethodsBlood serum and tissue metabolite levels were determined in Human Addison's disease (AD) patients as well as in mouse models of systemic and liver-specific GR loss-of-function (AAV-miR-GR) with or without dexamethasone (DEX) treatments. Body composition and neuromuscular and metabolic function tests were conducted in vivo and ex vivo, the latter using precision cut liver slices.ResultsA serum metabolite signature of impaired urea cycle function (i.e. higher [ARG]:[ORN + CIT]) was observed in human (CTRL: 0.45 ± 0.03, AD: 1.29 ± 0.04; p < 0.001) and mouse (AAV-miR-NC: 0.97 ± 0.13, AAV-miR-GR: 2.20 ± 0.19; p < 0.001) GC/GR loss-of-function, with similar patterns also observed in liver. Serum urea levels were consistently affected by GC/GR gain- (∼+32%) and loss (∼−30%) -of-function. Combined liver-specific GR loss-of-function with DEX treatment revealed a tissue-autonomous role for the GR to coordinate an upregulation of liver urea production rate in vivo and ex vivo, and prevent hyperammonaemia and associated neuromuscular dysfunction in vivo. Liver mRNA expression profiling and GR-cistrome mining identified Arginase I (ARG1) a urea cycle gene targeted by the liver GR.ConclusionsThe liver GR controls systemic and liver urea cycle function by transcriptional regulation of ARG1 expression.

Walker, AJ, McFadden, BA, Sanders, DJ, Bozzini, BN, Conway, SP, and Arent, SM. Early season hormonal and biochemical changes in Division I field hockey players: is fitness protective? J Strength Cond Res 34(4): 975–981, 2020—The purpose was to evaluate changes in hormonal and biochemical markers as a result of the accumulated stress of the initial 4-week training block in field hockey players. Women's Division I field hockey players (N = 22; Mage = 19.7 ± 1.1 years) performed testing before the start of preseason (A1) that included body composition (%BF), vertical jump, and V̇o 2max. Blood draws were conducted at A1 to assess creatine kinase (CK), iron (Fe), hemoglobin (HGB), hematocrit (HCT), percent saturation (%sat), total cortisol (TCORT), free cortisol (FCORT), interleukin-6 (IL-6), sex hormone–binding globulin (SHBG), prolactin (PRL), vitamin D (vitD), and thyroxine (T3). Blood draws were repeated 4 weeks later (A2). Athletes were monitored during this training block, which included 2 weeks of preseason and the first 2 weeks of the season, using heart rate monitors to determine energy expenditure (Kcal) and training load. There were significant disruptions in TCORT, FCORT, T3, CK, Fe, and SHBG (p < 0.05) from A1 to A2. V̇o 2max accounted for 31% (p < 0.05) of the variance in TCORT and %BF accounting for an additional 20.1% (p < 0.05). V̇o 2max accounted for 32.7% (p < 0.05) of the variance in FCORT. %BF accounted for 48.9% (p < 0.05) of the variance in T3. Kcal was positively correlated with V̇o 2max (p < 0.05) and negatively correlated with %BF (p < 0.05). Athletes with higher V̇o 2max and lower %BF may be capable of a higher work output and therefore more likely to experience increased physiological disruptions during intense training. The high-volume nature of preseason and differences in athlete fitness capabilities require coaches to manage players at an individual level to maintain athlete readiness.

Normal gut function is vital for animal survival, and deviations from such function can contribute to malnutrition, inflammation, increased susceptibility to pathogens, diabetes, neurodegenerative diseases, and cancer. In the fruit fly Drosophila melanogaster, mutation of the gene drop-dead (drd) results in defective gut function, as measured by enlargement of the crop and reduced food movement through the gut, and drd mutation also causes the unrelated phenotypes of neurodegeneration, early adult lethality and female sterility. In the current work, adult drd mutant flies are also shown to lack the peritrophic matrix (PM), an extracellular barrier that lines the lumen of the midgut and is found in many insects including flies, mosquitos and termites. The use of a drd-gal4 construct to drive a GFP reporter in late pupae and adults revealed drd expression in the anterior cardia, which is the site of PM synthesis in Drosophila. Moreover, the ability of drd knockdown or rescue with several gal4 drivers to recapitulate or rescue the gut phenotypes (lack of a PM, reduced defecation, and reduced adult survival 10-40 days post-eclosion) was correlated to the level of expression of each driver in the anterior cardia. Surprisingly, however, knocking down drd expression only in adult flies, which has previously been shown not to affect survival, eliminated the PM without reducing defecation rate. These results demonstrate that drd mutant flies have a novel phenotype, the absence of a PM, which is functionally separable from the previously described gut dysfunction observed in these flies. As the first mutant Drosophila strain reported to lack a PM, drd mutants will be a useful tool for studying the synthesis of this structure.

Background Antioxidant supplementation may provide protection against negative health consequences of oxygen-free radicals caused by aerobic and re-sustained exercise. The aim is to find out the efficacy of antioxidant rich nutrient bar supplementation on the antioxidant status and physical fitness components of athletes. Method Forty track and field athletes were selected using convenience sampling technique. The Human Research Ethics Committee of PSG College of Arts and Science, Coimbatore approved the study. Voluntary participation of the subjects was emphasized and a written consent was obtained from them in order to be included in the study. An interview schedule was formulated to collect general information such as name, age, gender, and academic qualifications, as well as information pertaining to the types of sporting activity, duration of the activity per day, number of years involved in the respective sports and level of participation (district/state/national). Nutrient bars each weighing 50gm were prepared with rolled oats, pumpkin seeds, dehydrated carrots, flax seeds, peanuts, almonds, honey and date syrup as ingredients. Each athlete was provided with two bars containing 110 mg of antioxidant. The prepared bars were analyzed for their total anti-oxidant content using DPPH method. The experimental group (n = 20) was supplemented with the formulated nutrient bars every day for a period of 3 months, and the control group (n = 20) with a placebo. Bio-chemical parameters namely GSH, GSH-px, SOD, vitamin C, serum LPO and physical fitness tests such as 12 minutes test, speed test, step test, push-ups test, vertical jump test and hexagon agility test were assessed at baseline and after 90 days. Statistical analysis was performed using SPSS (version 15). ResultsThe mean age was 18 ± 3.2 yrs. Sixty percent of the selected athletes were males and 40 % females. The main source of nutrition information was from coaches (56 %) and magazines (30 %). The athletes of the experimental group, when compared with the control group, showed a significant increase in serum levels from 37.42 ± 12.01 units/min/ml to 42.08 ± 13.16 units/min/ml of SOD (p = 0.000). LPO increased from 2.89 ± 0.82 μg/ml to 3.80 ± 1.37 μg/ml (p = 0.005), GSH increased from 209.76 ± 8.17 μg/ml to 244.58 ± 33.36 μg/ml (p = 0.000). The mean levels of vitamin C and GSH-px decreased minimally in the experimental group but significantly in the control group. Significant improvement in all six physical fitness tests namely 12 minutes test (from 1.44 ± 0.142 to 1.56 ± 0.134) , speed test (from 6.5940 ± 0.258 to 6.7435 ± 0.25) step test (from 68.65 ± 5.51 to 78.35 ± 4.004) push-ups (from 22.25 ± 3.97 to 29.70 ± 3.40), vertical jumps test (from 60.00 ± 5.620 to 63.75 ± 6.043) and hexagon agility tests (from 12.255 ± 0.42 to 12.400 ± 0.51) were observed in the experimental group). However in the control group, the improvements were significant only in the 12 minutes test, step test and speed test. Conclusion Supplementation of athletes with antioxidant-rich...

No abstract

No abstract

No abstract

No abstract