Pharmacological hypogonadism impairs molecular transducers of exercise-induced muscle growth in humans

Background: The relative role of skeletal muscle mechano-transduction in comparison with systemic hormones, such as testosterone (T), in regulating hypertrophic responses to exercise is contentious. We investigated the mechanistic effects of chemical endogenous T depletion adjuvant to 6weeks of resistance exercise training (RET) on muscle mass, function, myogenic regulatory factors, and muscle anabolic signalling in younger men. Methods: Non-hypogonadal men (n=16; 18–30years) were randomized in a double-blinded fashion to receive placebo (P, saline n=8) or the GnRH analogue, Goserelin [Zoladex (Z), 3.6mg, n=8], injections, before 6weeks of supervised whole-body RET. Participants underwent dual-energy X-ray absorptiometry (DXA), ultrasound of m. vastus lateralis (VL), and VL biopsies for assessment of cumulative muscle protein synthesis (MPS), myogenic gene expression, and anabolic signalling pathway responses. Results: Zoladex suppressed endogenous T to within the hypogonadal range and was well tolerated; suppression was associated with blunted fat free mass [Z: 55.4±2.8 to 55.8±3.1kg, P=0.61 vs. P: 55.9±1.7 to 57.4±1.7kg, P=0.006, effect size (ES)=0.31], composite strength (Z: 40±2.3% vs. P: 49.8±3.3%, P=0.03, ES=1.4), and muscle thickness (Z: 2.7±0.4 to 2.69±0.36cm, P>0.99 vs. P: 2.74±0.32 to 2.91±0.32cm, P0.99 vs. P: 1.9 fold, P0.99 vs. P: 4.7 fold, P=0.0005, ES=0.68; myogenin: Z: 1.3 fold, P>0.99 vs. P: 2.7 fold, P=0.002, ES=0.72), RNA/DNA (Z: 0.47±0.03 to 0.53±0.03, P=0.31 vs. P: 0.50±0.01 to 0.64±0.04, P=0.003, ES=0.72), and RNA/ASP (Z: 5.8±0.4 to 6.8±0.5, P>0.99 vs. P: 6.5±0.2 to 8.9±1.1, P=0.008, ES=0.63) ratios, as well as acute RET-induced phosphorylation of growth signalling proteins (e.g. AKTser473: Z: 2.74±0.6, P=0.2 vs. P: 5.5±1.1 fold change, P0.99 vs. P: 3.6±1 fold change, P=0.002, ES=0.53). Both MPS (Z: 1.45±0.11 to 1.50±0.06%·day−1, P=0.99 vs. P: 1.5±0.12 to 2.0±0.15%·day−1, P=0.01, ES=0.97) and (extrapolated) muscle protein breakdown (Z: 93.16±7.8 vs. P: 129.1±13.8g·day−1, P=0.04, ES=0.92) were reduced with hypogonadism result in lower net protein turnover (3.9±1.1 vs. 1.2±1.1g·day−1, P=0.04, ES=0.95). Conclusions: We conclude that endogenous T sufficiency has a central role in the up-regulation of molecular transducers of RET-induced muscle hypertrophy in humans that cannot be overcome by muscle mechano-transduction alone

The effect of a very low-calorie diet (VLCD) with and without concomitant resistance exercise training (RET) or high-intensity interval training (HIIT) on body composition, muscle function and metabolism

Background: Weight loss is beneficial for health in many aspects, including reducing the risk of various diseases such as type 2 diabetes mellitus, cardiovascular disease, respiratory problems and many more. A very low-calorie diet is one of the methods that can provide rapid weight loss. Unfortunately, there are concerns regards to muscle and lean mass loss with the weight loss process. Exercises particularly resistant exercise training (RET) is known to stimulate muscle growth; however, research combining RET with VLCD is scarce. High-intensity interval training (HIIT) has recently emerged as an ‘efficient’ exercise that can fit many busy lifestyles. However, no study has been done to combine HIIT with VLCD to compare its benefit with diet only or with RET. Objectives: To assess for any significant differences in the outcomes from VLCD only, VLCD with RET and VLCD with HIIT interventions, focusing on changes in lean and muscle mass, muscle protein synthesis rate, muscle function in the form of muscle strength, metabolic markers including lipid profiles and glucose homeostasis, cardiovascular function, and cardiorespiratory fitness. Design: Overweight/obese (BMI≥27) middle age (30 to 60-year old) males were recruited, randomly assigned to three groups either VLCD only (VLCD+O), VLCD with RET (VLCD+R) or VLCD+HIIT (VLCD+H). Interventions were for six weeks. Investigations and procedures include DXA scan, ultrasound scan of muscle structure and blood flow, echocardiogram of the heart, oral glucose tolerance test for insulin and glucose level, blood sampling, saliva collection and muscle biopsy involving stable isotope deuterium oxide to measure muscle protein synthesis rate. Conclusion: All groups showed significant total weight, fat mass, and lean mass loss. Despite the lean mass loss, all groups had improvement in metabolic markers, including glucose homeostasis and lipid profiles and had no reduction in muscle strength. Incorporating HIIT with VLCD showed a statistically significant higher muscle protein synthesis rate compared to VLCD alone while incorporating RET showed a significant increase in strength compared to the other groups

The effect of a very low-calorie diet (VLCD) with and without concomitant resistance exercise training (RET) or high-intensity interval training (HIIT) on body composition, muscle function and metabolism

Background: Weight loss is beneficial for health in many aspects, including reducing the risk of various diseases such as type 2 diabetes mellitus, cardiovascular disease, respiratory problems and many more. A very low-calorie diet is one of the methods that can provide rapid weight loss. Unfortunately, there are concerns regards to muscle and lean mass loss with the weight loss process. Exercises particularly resistant exercise training (RET) is known to stimulate muscle growth; however, research combining RET with VLCD is scarce. High-intensity interval training (HIIT) has recently emerged as an ‘efficient’ exercise that can fit many busy lifestyles. However, no study has been done to combine HIIT with VLCD to compare its benefit with diet only or with RET. Objectives: To assess for any significant differences in the outcomes from VLCD only, VLCD with RET and VLCD with HIIT interventions, focusing on changes in lean and muscle mass, muscle protein synthesis rate, muscle function in the form of muscle strength, metabolic markers including lipid profiles and glucose homeostasis, cardiovascular function, and cardiorespiratory fitness. Design: Overweight/obese (BMI≥27) middle age (30 to 60-year old) males were recruited, randomly assigned to three groups either VLCD only (VLCD+O), VLCD with RET (VLCD+R) or VLCD+HIIT (VLCD+H). Interventions were for six weeks. Investigations and procedures include DXA scan, ultrasound scan of muscle structure and blood flow, echocardiogram of the heart, oral glucose tolerance test for insulin and glucose level, blood sampling, saliva collection and muscle biopsy involving stable isotope deuterium oxide to measure muscle protein synthesis rate. Conclusion: All groups showed significant total weight, fat mass, and lean mass loss. Despite the lean mass loss, all groups had improvement in metabolic markers, including glucose homeostasis and lipid profiles and had no reduction in muscle strength. Incorporating HIIT with VLCD showed a statistically significant higher muscle protein synthesis rate compared to VLCD alone while incorporating RET showed a significant increase in strength compared to the other groups

Simultaneous action of surfactant modified clinoptilolite: adsorbent of dyes and antibacterial agent

In this study, the simultaneous action of surfactant modified clinoptilolite (SMC) as adsorbent for dyes and its antibacterial activity was investigated. Methylene blue (MB) and acid orange 7 (AO7) represent cationic and anionic dyes, respectively were used as adsorbate in this study and the antibacterial activity was studied against Gram-negative (Escherichia coli ATCC 11229) and Gram-positive bacteria (Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 2921). Initially, natural zeolite clinoptilolite was modified with 3 different concentrations (0.1, 1.0 and 4.0 mM) of cationic surfactant hexadecyltrimethyl ammonium bromide (HDTMA-Br). The SMC samples were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), amount of HDTMA adsorbed and dispersion behaviour. Result from XRD shows that the HDTMA-Br molecules caused no effect on primary structure of the clinoptilolite since the clinoptilolite structure remained the same after modification with HDTMA-Br. Compared to the unmodified clinoptilolite, FTIR spectra of the SMC shows peak corresponds to C-H stretches which proved the attachment of HDTMA onto the clinoptilolite surfaces. In the dispersion behaviour study, SMC samples were located at the adjacent phase between the water and oil mixture. The amount of HDTMA-Br adsorbed onto the clinoptilolite increased with the increasing concentrations of the surfactant. The use of SMC as adsorbent and antibacterial agent were further studied against the ionic dyes and bacteria simultaneously. The results show that the adsorption capacity of SMC towards both ionic dyes increase with the increasing HDTMA-Br concentration. While for the antibacterial activity, the number of colony forming unit of bacteria seem to be highly reduced at the highest concentration of the HDTMA (4.0 mM) attached on the clinoptilolite. Hence, this study had shown that SMC has high adsorption capacity towards the ionic dyes at the same time reducing the growth of both Gram positive and negative bacteria in aquoes solution

Heat Stress Effects on Leaf Physiological Performances, Vegetative Growth and Grain Yield of Grain Corn (Zea mays L.)

The impact of climate change on agricultural production will be most pronounced in tropical and subtropical regions, with numerous climate modeling studies predicting more occurrences of heat waves in the future. Elevated temperatures resulting from global warming pose a significant threat to the agricultural sector, as warmer conditions can hinder plant growth and development, leading to reduced crop yields or even crop failure under extreme circumstances. Therefore, this study aimed to determine the effects of ambient, non-heated (30 °C) and heat stress conditions (38 °C) on the plant physiological responses, growth and yield of grain corn during both the vegetative and reproductive stages. The results demonstrated that exposure to heat stress for 7 days significantly impacted the physiological performance of the plants, resulting in a substantial 46.9% reduction in net photosynthetic rate. However, prolonged exposure to heat for 28 days caused even more severe effects, with a 72.5% reduction in net photosynthetic rate. Although the effects of heat stress on vegetative growth were not apparent after 7 days, the plants exhibited severe damage after 28 days of heat stress treatment. During the flowering stage, heat stress led to significant reduction in kernel set, total kernel number, and grain weight of grain corn by 45%, 41%, and 46%, respectively. Poor and scattered kernel set on cobs during the heat stress treatment at the anthesis period indicated damage to pollen grains, failed pollination, and fertilization. These findings highlight the vulnerability of grain corn varieties cultivated in Malaysia to the negative impacts of heat stress, leading to potential losses in production yield