Effects of a leucine-rich diet on body composition during nutritional recovery in rats

OBJECTIVE: Protein malnutrition is characterized by a number of morphologic and physiologic alterations, including intestinal mucosal atrophy and impaired nutrient absorption. Impaired absorption accentuates nutritional deficiency and accelerates body weight loss and changes in body chemistry. Because leucine is a ketogenic and oxidative amino acid and stimulates the protein synthesis, we examined the ability of young rats to recover from protein malnutrition by feeding them a control balanced or a leucine-rich diet for 60 d.METHODS: At the end of the 60-d period, body, liver, and muscle weights; glucose, methionine, and leucine intestinal absorption; and carcass chemical composition were evaluated.RESULTS: Body weight gain was higher in the control balanced and leucine-rich groups than in control rats, indicating that adequate refeeding allows body weight to recover in these groups. Methionine and glucose absorptions were impaired in malnourished rats but were restored after nutritional recovery. The leucine-rich diet resulted in an increase in carcass collagen nitrogen but maintained the carcass structural nitrogen.CONCLUSIONS: These results indicated that leucine supplementation during nutritional recovery from protein malnutrition improves protein carcass restoration. However, the precise mechanism of the leucine effects involved in this response remains to be elucidated.

Effects of soy protein and resistance exercise on body composition and blood lipids in postmenopausal women

Objective: To assess the effect of soy protein and progressive resistance training on body composition and lipids in postmenopausal women.Design: In a controlled trial, 46 postmenopausal women were randomized to one of four groups: 25 g of soy protein (SP, n = 10), 25 g of soy protein plus resistance exercise (SPE, n = 14), 25 g of maltodextrine (placebo) (PL, n = 11), or placebo plus resistance exercise (PLE, n = 11). Progressive resistance training was held three times a week for 16 weeks and included 8 exercises (3 series of 8-12 repetitions). At baseline and after 16 weeks, body mass index, waist circumference (WC), body fat, muscle mass and serum lipid levels were measured. To confirm isoflavone absorption, urinary concentrations were determined. The t-test of Student and ANOVA were used in the statistical analysis.Results: Subjects were classified as overweight and showed android fat distribution: Urinary isoflavone excretion indicated compliance to soy protein treatment. After 16 weeks of intervention, both SPE and PLE groups showed a significant increase of 1.3 kg in muscle mass and reduction in WC of -1.4 and -2.1 cm, respectively (p < 0.05). Significant decreases in the mean values of total cholesterol and LDL (-29.0 and -24.0 mg/dL, p < 0.001 and p < 0.006, respectively) were observed in the users of soy protein alone (SP).Conclusions: Soy protein supplementation did not influence the indicators of body composition. However, it exerted possible favorable effects on lipid profile in postmenopausal women. The increase in muscle mass and reduction in abdominal fat were correlated with resistance training. (c) 2006 Elsevier B.V.. All rights reserved.

Quality traits and lipid composition of meat from Nellore young bulls fed with different oils either protected or unprotected from rumen degradation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Heart failure alters MyoD and MRF4 expressions in rat skeletal muscle

Heart failure (HF) is characterized by a skeletal muscle myopathy with increased expression of fast myosin heavy chains (MHCs). The skeletal muscle-specific molecular regulatory mechanisms controlling MHC expression during HF have not been described. Myogenic regulatory factors (MRFs), a family of transcriptional factors that control the expression of several skeletal muscle-specific genes, may be related to these alterations. This investigation was undertaken in order to examine potential relationships between MRF mRNA expression and MHC protein isoforms in Wistar rat skeletal muscle with monocrotaline-induced HF. We studied soleus (Sol) and extensor digitorum longus (EDL) muscles from both HF and control Wistar rats. MyoD, myogenin and MRF4 contents were determined using reverse transcription-polymerase chain reaction while MHC isoforms were separated using polyacrylamide gel electrophoresis. Despite no change in MHC composition of Wistar rat skeletal muscles with HF, the mRNA relative expression of MyoD in Sol and EDL muscles and that of MRF4 in Sol muscle were significantly reduced, whereas myogenin was not changed in both muscles. This down-regulation in the mRNA relative expression of MRF4 in Sol was associated with atrophy in response to HF while these alterations were not present in EDL muscle. Taken together, our results show a potential role for MRFs in skeletal muscle myopathy during HF. © 2006 Blackwell Science Ltd.

Dietary fish oil replacement with lard and soybean oil affects triacylglycerol and phospholipid muscle and liver docosahexaenoic acid content but not in the brain and eyes of surubim juveniles Pseudoplatystoma sp

Triplicate groups of juvenile suribim were fed for 183 days one of four different isonitrogenous (47.6% crude protein) and isolipidic (18.7% lipid) diets formulated using three different lipid sources: 100% fish oil (FO, diet 1); 100% pig lard (L, diet 2); 100% soybean oil (SO, diet 3), and FO/L/SO (1:1:1, w/w/w; diet 4). The tissue levels of fatty acids 18:2n - 6 and 18:3n - 3 decreased relative to corresponding dietary fatty acid values. The 20:5n - 3 and 22:6n - 3 composition of muscle and liver neutral lipids were linearly correlated with corresponding dietary fatty acid composition. In contrast, the 22:6n - 3 composition of the brain and eye were similar among treatments. The 22:6n - 3 level was enriched in all tissues, particularly in the neural tissues. Similar results were observed for tissue polar lipids: fatty acids content reflected dietary composition, with the exception of the 22:6n - 3 level, which showed enrichment and no differences between groups. Given these results, the importance of the biochemical functions (transport and/or metabolism) of 22:6n - 3 in the development of the neural system of surubim warrants further investigation. © Springer Science+Business Media B.V. 2008.

Tissue composition and muscularity of lamb legs fed with sunflower seeds and vitamin E

The purpose of this study was to evaluate the tissue composition and carcass muscularity of 32 legs of Ile de France lambs fed with diets containing sunflower seeds and vitamin E, with mean body weight of 15 kg, lodged in individual pens at 15 kg and slaughtered at 32 kg of body weight. The treatments influenced (P<0,05) leg weight, femur length and muscle: bone ratio, being the highest values (2,13 kg, 16,19 cm and 7,38, respectively) in lambs that received diet without sunflower seeds and vitamin E. The other variables were not affected (P>0,05) by the treatments. The interaction of the sunflower and vitamin E was positive for bone total weights and intramuscular fat.

Muscular strength, bone density and body composition of a woman with systemic lupus erythematosus submitted to a resistance training program: A case report

Introduction. Physical activity can provide long-term benefits for systemic lupus erythematosus (SLE). Objective. This study sought to demonstrate the effects of progressive resistance training on the muscular strength, bone mineral density (BMD) and body composition of pre-menopausal women with SLE undergoing glucocorticoid (GC) treatment. Materials and Methods. This is the case report of a 43-year-old African-South American premenopausal woman with non-extensive SLE and low bone density. A six-month program with three bimonthly cycles of 70%, 80%, and 90% intensity according to the 10 maximum-repetition test was used. Dual-energy X-ray absorptiometry (DXA) was used to measure the BMD, T-scores and body composition, and indirect fluorescence was used to measure the levels of antinuclear antibodies. Student's t-test was used. Results. Statistical improvement was noted in all strength exercises, including the 45° leg press (Δ%=+50%, p<0.001) and knee extension (Δ%=+15%, p=0.003) to maintain the BMD of the L2-L4 lumbar (Δ%=+0.031%; p=0.46) as well as the trochanter (Δ%=+0.037%; p=0.31) and BMI (Δ%=-0.8, p=0.54). Conclusion. In this case study, the presented methodology had a positive effect on strength and contributed to the maintenance of BMD and body composition in a woman with SLE undergoing GC treatment. © 2012 Revista Andaluza de Medicina del Deporte.

Evaluation of nutritional indicators and body composition in patients with advanced liver disease enrolled for liver transplantation

PURPOSE: Malnutrition is prevalent in patients with advanced liver disease (LD) related to multifactorial causes. Fluid retention can underestimate the nutritional status based on anthropometric measures. We evaluated nutritional indicators and body composition (BC) in patients with liver cirrhosis and correlated them with LD severity. METHODS: Forty three patients with LD enrolled for liver transplantation were evaluated by Anthropometric measures, subjective evaluation (Global Assessment of Nutritional Status - SGA) and biochemical indicators. Single-frequency electrical bioimpedance (SFE-BIA) was used to evaluate body composition (BC). It measured resistance (R), reactance (Xc) and the phase angle (PA). LD severity was estimated by Child-Pugh and Meld criteria (Model for End-Stage Liver Disease). RESULTS: Child-Pugh index between patients was 7.11±1.70 and Meld was 12.23±4.22. Arm Circumference, Arm Muscle Circumference and Arm Muscle Area, SGA, hemoglobin, hematocrit and albumin showed better correlation with disease severity. Xc and PA showed correlation both with Meld and Child-Pugh score when BC were evaluated. PA was depleted in 55.8% of the patients. CONCLUSIONS: Diagnosis of malnutrition varied according to the method. Global assessment of nutritional status showed better correlation with disease severity than with objective methods. Single-frequency electrical bioimpedance for body composition analysis in cirrhotic patients must be cautiously used; however, primary vectors seems to be valid and promising in clinical practice.

Effects of resistance training frequency on body composition and metabolics and inflammatory markers in overweight postmenopausal women

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Autonomic modulation and its relation with body composition in swimmers

This study compared autonomic modulation in swimmers and non-athletes in relation to body composition. A total of 28 athletes with a mean age of 19.7 +/- 2.9 years were evaluated who had at least 2 years of swimming training, trained approximately 7,000 m per day, with a frequency of 5 days per week, and who competed at national level. The control group was made up of 21 volunteers (23.0 +/- 2.5 years), who did not practice regular physical activity (<2 hours per week). Body composition was estimated using dual-energy x-ray absorptiometry, and autonomic modulation was assessed by heart rate variability (HRV). The results show that there were significant differences in autonomic modulation and body composition between the groups, and that the athletes had a higher overall variability (standard deviation of all normal intervals between consecutive heart beats [SDNN]: 78.1 [72.5-93.5] x 61.1 [56.4-75.7], p = 0.022) and greater autonomic balance (LF/HF: 0.96 [0.88-1.35] x 0.71 [0.56-0.93], p = 0.023), compared with the non-athletes, respectively. In addition, a moderate and positive relation was obtained between fat-free mass and the square root of the squared differences between consecutive heartbeat intervals (RMSSD: r = 0.526, p = 0.004 x r = 0.456, p = 0.038), (SDNN: r = 0.617, p = 0.001 x r = 0.571, p = 0.007) and low frequency (LFms(2): r = 0.517, p = 0.005 3 r = 0.600, p = 0.004) in the athletes and non-athletes, respectively, without a correlation between fat mass (FM). The conclusion is that young highly trained swimmers had lower FM, increased fat-free mass, and better HRV than young adult non-athletes and suggests that a lower quantity of FM and, especially, a greater fat-free mass (FFM) are linked to better autonomic modulation. Thus, this study could contribute to coaches and trainers establishing greater performance by better autonomic modulation and greater quantity of FFM.

Processing yield and chemical composition of rainbow trout (Oncorhynchus mykiss) with regard to body weight

The influence of weight (W) category of the rainbow trout on processing yield and chemical composition of the entire eviscerated fish and fish fillet was analyzed. A completely randomized design was employed for processing variables (W1 = 300 to 370 g and W2 = 371 to 440) coupled to a 2 x 2 factorial scheme for the chemical composition (W1 and W2 and forms of presentation: fillet and whole eviscerated fish). W1 showed higher yield for entire eviscerated fish (83.00%) and head (13.27%), but a lower yield for the viscera (17.00%), when compared to W2. We did not affect abdominal muscle yield, fillet with or without skin, skin percentage and residues. There were significant differences between W for moisture (W1 = 72.30% and W2 = 71.15%) and lipids (CP1 = 7.96% and CP2 = 9.04%) rates. Fillet moisture contents (73.74%) and crude protein (19.05%) were higher (p < 0.01) than for entire eviscerated fish (69.71% and 17.81%, respectively). Ash (2.15%) and lipid (10.48%) rates were higher (p < 0.01) for entire fish when compared to those of fillets (1.16% and 6.52%, respectively). The slaughter of fish weighing between 300 and 370 g and their fillets are more adequate for the market.

Effects of high and low volume of strength training on muscle strength, muscle volume and lipid profile in postmenopausal women

Changes in lipid profile are considered a risk factor for cardiovascular disease (CVD), especially in postmenopausal woman who have been associated with age-related loss of muscle mass. The beneficial role of aerobic exercise in the prevention of CVD has been well documented. However, the effect of strength training has not been established. The purpose of this study was to determine the changes of lipoprotein levels after 12 weeks of different volumes of strength training and its correlation with strength and muscle volume in postmenopausal women. The participants were randomized into three groups: low volume (LVST; n = 12, 1 set) and high volume of strength training (HVST; n = 11, 3 sets), or control group (n = 12). Training groups performed 12 weeks of supervised strength exercises, 15 maximum repetitions, five times a week, 20 minutes for LVST and 40 minutes for HVST for each training session. Measurements included body composition, strength and muscle volume, as well as blood analysis (glucose, total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein) pre- and post-training. The HVST and LVST improved the one-repetition maximum knee extension strength (p < 0.001), maximal dynamic strength (p < 0.001), and muscle volume (p = 0.048). Post-training triglyceride was lower in HVST when compared to LVST and the control group (p = 0.047). Even though they present the same neuromuscular and morphological adaptations in postmenopausal women, the HVST is more effective than LVST in improving the lipid profile of postmenopausal woman, and can be considered as an ideal program of intervention to reverse changes in lipid metabolism commonly found in this group. Copyright (C) 2014, The Society of Chinese Scholars on Exercise Physiology and Fitness. Published by Elsevier (Singapore) Pte Ltd. All rights reserved.

Downhill running excessive training inhibits hypertrophy in mice skeletal muscles with different fiber type composition

The aim of this study was to verify the effects of running overtraining protocols performed in downhill, uphill, and without inclination on the proteins related to hypertrophy signaling pathway in extensor digitorum longus (EDL) and soleus of C57BL/6 mice. We also performed histological and stereological analyses. Rodents were divided into control (CT; sedentary mice), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up), and overtrained by running without inclination (OTR). The incremental load, exhaustive, and grip force tests were used as performance evaluation parameters. 36 h after the grip force test, EDL and soleus were removed and immediately used for immunoblotting analysis or stored at -80°C for histological and stereological analyses. For EDL, OTR/down decreased the protein kinase B (Akt) and tuberous sclerosis protein 2 (TSC2) phosphorylation (p), and increased myostatin, receptor-activated Smads (pSMAD2-3), and insulin receptor substrate-1 (pIRS-1; Ser307/636). OTR/down also presented low and high relative proportions of cytoplasm and connective tissue, respectively. OTR/up increased the mammalian target of rapamycin (pmTOR), 70-kDa ribosomal protein S6 kinase 1 (pS6K1) and pSMAD2-3, and decreased pTSC2. OTR decreased pTSC2 and increased pIRS-1 (Ser636). For soleus, OTR/down increased S6 ribosomal protein (pS6RP) and pSMAD2-3, and decreased pIRS-1 (Ser639). OTR/up decreased pS6K1, pS6RP and pIRS-1 (Ser639), and increased pTSC2 (Ser939), and pSMAD2-3. OTR increased pS6RP, 4E-binding protein-1 (p4E-BP1), pTSC2 (Ser939), and pSMAD2-3, and decreased pIRS-1 (Ser639). In summary, OTR/down inhibited the skeletal muscle hypertrophy with concomitant signs of atrophy in EDL. The effects of OTR/up and OTR depended on the analyzed skeletal muscle type. J. Cell. Physiol. 9999: 1-12, 2015. © 2015 Wiley Periodicals, Inc.

Metabolic and functional effects of beta-hydroxy-beta-methylbutyrate (HMB) supplementation in skeletal muscle

Beta-hydroxy-beta-methylbutyrate (HMB) is a metabolite derived from leucine. The anti-catabolic effect of HMB is well documented but its effect upon skeletal muscle strength and fatigue is still uncertain. In the present study, male Wistar rats were supplemented with HMB (320 mg/kg per day) for 4 weeks. Placebo group received saline solution only. Muscle strength (twitch and tetanic force) and resistance to acute muscle fatigue of the gastrocnemius muscle were evaluated by direct electrical stimulation of the sciatic nerve. The content of ATP and glycogen in red and white portions of gastrocnemius muscle were also evaluated. The effect of HMB on citrate synthase (CS) activity was also investigated. Muscle tetanic force was increased by HMB supplementation. No change was observed in time to peak of contraction and relaxation time. Resistance to acute muscle fatigue during intense contractile activity was also improved after HMB supplementation. Glycogen content was increased in both white (by fivefold) and red (by fourfold) portions of gastrocnemius muscle. HMB supplementation also increased the ATP content in red (by twofold) and white (1.2-fold) portions of gastrocnemius muscle. CS activity was increased by twofold in red portion of gastrocnemius muscle. These results support the proposition that HMB supplementation have marked change in oxidative metabolism improving muscle strength generation and performance during intense contractions.