scholarly journals Body composition and grip strength are improved in transgenic sickle mice fed a high-protein diet

2015 ◽  
Vol 4 ◽  
Author(s):  
Patrice L. Capers ◽  
Hyacinth I. Hyacinth ◽  
Shayla Cue ◽  
Prasanthi Chappa ◽  
Tatyana Vikulina ◽  
...  
Keyword(s):  
Body Composition ◽  
Weight Gain ◽  
Grip Strength ◽  
Bone Mineral ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Standard Diet ◽  
Mineral Density ◽  
Improve Body Composition

AbstractKey pathophysiology of sickle cell anaemia includes compensatory erythropoiesis, vascular injury and chronic inflammation, which divert amino acids from tissue deposition for growth/weight gain and muscle formation. We hypothesised that sickle mice maintained on an isoenergetic diet with a high percentage of energy derived from protein (35 %), as opposed to a standard diet with 20 % of energy derived from protein, would improve body composition, bone mass and grip strength. Male Berkeley transgenic sickle mice (S;n8–12) were fed either 20 % (S20) or 35 % (S35) diets for 3 months. Grip strength (BIOSEB meter) and body composition (dual-energy X-ray absorptiometry scan) were measured. After 3 months, control mice had the highest bone mineral density (BMD) and bone mineral content (BMC) (P < 0·005). S35 mice had the largest increase in grip strength. A two-way ANOVA of change in grip strength (P = 0·043) attributed this difference to genotype (P = 0·025) and a trend in type of diet (P = 0·067).l-Arginine (l-Arg) supplementation of the 20 % diet was explored, as a possible mechanism for improvement obtained with the 35 % diet. Townes transgenic sickle mice (TS;n6–9) received 0·8, 1·6, 3·2 or 6·4 %l-Arg based on the same protocol and outcome measures used for the S mice. TS mice fed 1·6 %l-Arg for 3 months (TS1.6) had the highest weight gain, BMD, BMC and lean body mass compared with other groups. TS3.2 mice showed significantly more improvement in grip strength than TS0·8 and TS1.6 mice (P < 0·05). In conclusion, the high-protein diet improved body composition and grip strength. Outcomes observed with TS1.6 and TS3.2 mice, respectively, confirm the hypothesis and reveall-Arg as part of the mechanism.

scholarly journals The Effects of a High-Protein Diet on Bone Mineral Density in Exercise-Trained Women: A 1-Year Investigation

2018 ◽  
Vol 3 (4) ◽  
pp. 62
Author(s):  
Jose Antonio ◽  
Anya Ellerbroek ◽  
Cassandra Carson
Keyword(s):  
Bone Mineral Density ◽  
Body Composition ◽  
Bone Mineral ◽  
Mineral Content ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Whole Body ◽  
Mineral Density ◽  
One Year

The effects of long-term high-protein consumption (i.e., >2.2 g/kg/day) are unclear as it relates to bone mineral content. Thus, the primary endpoint of this investigation was to determine if consuming a high-protein diet for one year affected various parameters of body composition in exercise-trained women. This investigation is a follow-up to a prior 6-month study. Subjects were instructed to consume a high-protein diet (>2.2 g/kg/day) for one year. Body composition was assessed via dual-energy X-ray absorptiometry (DXA). Subjects were instructed to keep a food diary (i.e., log their food ~three days per week for a year) via the mobile app MyFitnessPal®. Furthermore, a subset of subjects had their blood analyzed (i.e., basic metabolic panel). Subjects consumed a high-protein diet for one year (mean ± SD: 2.3 ± 1.1 grams per kilogram body weight daily [g/kg/day]). There were no significant changes for any measure of body composition over the course of the year (i.e., body weight, fat mass, lean body mass, percent fat, whole body bone mineral content, whole body T-score, whole body bone mineral density, lumbar bone mineral content, lumbar bone mineral density and lumbar T-score). In addition, we found no adverse effects on kidney function. Based on this 1-year within-subjects investigation, it is evident that a diet high in protein has no adverse effects on bone mineral density or kidney function.

Interactions of insulin-like growth factor (IGF)-II and growth hormone in vivo: circulating levels of IGF-I and IGF-binding proteins in transgenic mice

1997 ◽  
pp. 701-708 ◽  
Author(s):  
A Blackburn ◽  
RA Dressendorfer ◽  
WF Blum ◽  
M Erhard ◽  
G Brem ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Transgene Expression ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Standard Diet ◽  
Igf I ◽  
Igf Binding ◽  
B Mice

To study interactions between insulin-like growth factor-II (IGF-II) and growth hormone (GH) in vivo, we crossed hemizygous transgenic mice carrying phosphoenolpyruvate carboxykinase (PEPCK)-IGF-II fusion genes with hemizygous PEPCK-bovine GH (bGH) transgenic mice. Offspring harbouring both transgenes (IB), the IGF-II transgene (I) or the bGH transgene (B), and non-transgenic littermates (C) were obtained. Blood samples were taken before (end of week 12) and after (end of week 14) the mice had received a diet high in protein and low in carbohydrates to stimulate PEPCK promoter-controlled transgene expression. Mean serum GH concentrations of both B and IB mice corresponded to 900 ng/ml and increased more than twofold (P < 0.001) after 1 week of the high-protein diet. GH concentrations in controls and I mice were less than 20 ng/ml. Serum IGF-II concentrations in I and IB mice were three-to fourfold higher than those in C and B mice. Whereas IGF-II concentrations were not changed by the high-protein diet in the last two groups, serum IGF-II increased significantly in I (P < 0.001) and IB mice (P < 0.05). This increase was significantly (P < 0.05) less pronounced in IB than in C and I mice. Circulating IGF-I concentrations were about twofold (P < 0.001) higher in B and IB than in C and I mice, and showed a tendency to be lower in I than in C and in IB than in B mice when animals were maintained on the standard diet. The high-protein diet did not change circulating IGF-I concentrations in controls and B mice, but resulted in a significant reduction of serum IGF-I concentrations in I (P < 0.05) and IB mice (P < 0.001). Consequently, after PEPCK-IGF-II transgene expression was stimulated, serum IGF-I concentrations were significantly (P < 0.05) lower in I than in C and in IB than in B mice. Serum IGF-binding protein (IGFBP)-2 concentrations were significantly (P < 0.05) higher in I mice than in all other groups when mice were maintained on the standard diet, with a tendency to reduced IGFBP-2 concentrations in B mice. After the high-protein diet, serum IGFBP-2 concentrations did not change in C and I mice, but increased by two- to threefold in B and IB mice (P < 0.001). Serum IGFBP-3 concentrations tended to be greater in B and IB than in C and I mice, but these differences were mostly not significant. IGFBP-4 concentrations were significantly (P < 0.001) increased by GH overproduction in B and IB mice. Our data suggest that the reduction in circulating IGF-I concentrations by increased IGF-II is most probably due to the limited serum IGF binding capacity and the short half-life of free IGFs, rather than to a reduction in GH-dependent IGF-I production. Effects of GH overproduction on serum IGFBP-2 concentrations depend on dietary factors and may be both inhibitory and stimulatory.

scholarly journals Adaptive changes in the capacity of systems used for the synthesis of citrulline in rat liver mitochondria in response to high- and low-protein diets

1974 ◽  
Vol 142 (2) ◽  
pp. 359-364 ◽  
Author(s):  
J. D. McGivan ◽  
Norah M. Bradford ◽  
J. B. Chappell
Keyword(s):  
Nitrogen Source ◽  
High Protein Diet ◽  
Liver Mitochondria ◽  
High Protein ◽  
Protein Diet ◽  
Rat Liver Mitochondria ◽  
Standard Diet ◽  
Adaptive Changes ◽  
Low Protein ◽  
Citrulline Synthesis

1. Citrulline synthesis was measured in mitochondria from rats fed on a standard diet, a high-protein diet, or on glucose. 2. With NH4Cl as the nitrogen source the rate of citrulline synthesis was higher in mitochondria from rats fed on a high-protein diet than in those from rats fed on a standard diet. When rats were fed solely on glucose the rate of synthesis of citrulline from NH4Cl was very low. 3. With glutamate as the nitrogen source the relative rates of citrulline synthesis were much lower than when NH4Cl was present, but similar adaptive changes occurred. 4. The activity of the mitochondrial glutamate-transporting system increased two to three times on feeding rats on a high-protein diet, but the Km for glutamate was unchanged. 5. Adaptive changes in certain intramitochondrial enzymes were also measured. 6. The results were interpreted to indicate that when an excess of substrate was present, citrulline synthesis from NH4Cl was rate-limited by the intramitochondrial concentration of N-acetyl-glutamate, but citrulline synthesis from glutamate was rate-limited primarily by the activity of the glutamate-transporting system.

The effect of choice feeding during the rearing period on reproductive function in the gilt

2000 ◽  
Vol 2000 ◽  
pp. 102-102 ◽  
Author(s):  
S. R. L. Lucas ◽  
J. A. Rooke ◽  
V. C. Bland ◽  
A.G. Sinclair ◽  
S. A. Edwards
Keyword(s):  
Body Composition ◽  
Reproductive Function ◽  
High Protein Diet ◽  
Diet Selection ◽  
Growing Pigs ◽  
High Protein ◽  
Protein Source ◽  
Protein Diet ◽  
Choice Feeding ◽  
Growth And Reproduction

Previous studies (e.g. Cia et al. 1998) have shown that modification of body composition of the prepubertal gilt has effects on responsiveness of gilts to exogenous gonadotrophin. Growing pigs are able to select a diet from different foods differing in protein:energy ratio (Dalby 1998); however there is little evidence of what effect the conflicting nutritional demands of growth and reproduction have on diet selection. The objectives of the experiment were to quantify the effects of choice feeding on responsiveness of gilts to exogenous gonadotrophin (Cia et al. 1998) and to investigate the effect of protein source on diet selection as Jones et al.(2000) have observed selection by breeding gilts against a high protein diet containing fishmeal.

Glomerular size selectivity in nephrotic rats exposed to diets with different protein content

1987 ◽  
Vol 253 (2) ◽  
pp. F318-F327
Author(s):  
A. Remuzzi ◽  
C. Battaglia ◽  
L. Rossi ◽  
C. Zoja ◽  
G. Remuzzi
Keyword(s):  
High Protein Diet ◽  
Urinary Protein Excretion ◽  
Urinary Protein ◽  
High Protein ◽  
Protein Diet ◽  
Standard Diet ◽  
Size Selectivity ◽  
Protein Excretion ◽  
Fractional Clearance ◽  
Glomerular Size

Glomerular size-selective properties in animals made nephrotic by adriamycin (ADR) injection and fed standard (20% protein) or high-protein (35% protein) diets were investigated using dextran fractional clearances. To interpret filtration and dextran-sieving data, a theoretical approach previously developed for analysis of experimental data in healthy and nephrotic humans was used. Four types of hypothetical pore-radius distributions were compared in order to establish the best tool for describing membrane pore structure in normal and nephrotic rats. This analysis revealed that a spread distribution of pores, the lognormal probability distribution, is the most adequate in representing membrane intrinsic characteristics. ADR animals on standard diet developed massive proteinuria and a lower glomerular filtration rate (GFR) than control animals. High-protein feeding in ADR rats induced a further increase in urinary protein excretion and in GFR. Dextran fractional clearance was more elevated for larger dextran fractions (greater than 46 A) in ADR animals on the standard diet than in control rats. No differences were observed in dextran-sieving curves between ADR rats on the standard and high-protein diet. Theoretical analysis of filtration and fractional clearance data revealed comparable changes in the intrinsic parameters of glomerular size selectivity in the two groups of nephrotic animals. These observations indicate that increased traffic of plasma proteins through the glomerular capillary wall does not imply, in our experimental condition, a further loss of glomerular size-selective properties. The greater urinary protein excretion of ADR animals on high-protein diet than ADR animals on a standard diet cannot be explained by further impairment of glomerular size selectivity but more likely reflects hemodynamic changes.

scholarly journals High Protein Diet Induces Oxidative Stress in Rat Cerebral Cortex and Hypothalamus

2019 ◽  
Vol 20 (7) ◽  
pp. 1547 ◽  
Author(s):  
Ewa Żebrowska ◽  
Mateusz Maciejczyk ◽  
Małgorzata Żendzian-Piotrowska ◽  
Anna Zalewska ◽  
Adrian Chabowski
Keyword(s):  
Oxidative Stress ◽  
Cerebral Cortex ◽  
Oxidative Damage ◽  
Antioxidant Defense ◽  
High Protein Diet ◽  
Brain Structures ◽  
High Protein ◽  
Protein Diet ◽  
Standard Diet ◽  
The Impact

This is the first study to analyze the impact of high protein diet (HPD) on antioxidant defense, redox status, as well as oxidative damage on both a local and systemic level. Male Wistar rats were divided into two equal groups (n = 9): HPD (44% protein) and standard diet (CON; 24.2% protein). After eight weeks, glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT), superoxide dismutase-1 (SOD-1), reduced glutathione (GSH), uric acid (UA), total antioxidant (TAC)/oxidant status (TOS) as well as advanced glycation end products (AGE), 4-hydroxynonenal (4-HNE), and malondialdehyde (MDA) were analyzed in the serum/plasma, cerebral cortex, and hypothalamus of HPD and CON rats. HPD resulted in higher UA concentration and activity of GPx and CAT in the hypothalamus, whereas in the cerebral cortex these parameters remained unchanged. A significantly lower GSH content was demonstrated in the plasma and hypothalamus of HPD rats when compared to CON rats. Both brain structures expressed higher content of 4-HNE and MDA, whereas AGE was increased only in the hypothalamus of HPD animals. Despite the enhancement in antioxidant defense in the hypothalamus, this mechanism does not protect the hypothalamus from oxidative damage in rats. Hypothalamus is more susceptible to oxidative stress caused by HPD.

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