scholarly journals Modulation of the gut microbiota with antibiotic treatment suppresses whole body urea production in neonatal pigs

2013 ◽  
Vol 304 (3) ◽  
pp. G300-G310 ◽  
Author(s):  
Patrycja Puiman ◽  
Barbara Stoll ◽  
Lars Mølbak ◽  
Adrianus de Bruijn ◽  
Henk Schierbeek ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Gut Microbiota ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Urea Synthesis ◽  
Plasma Urea ◽  
Body Protein ◽  
Neonatal Pigs

We examined whether changes in the gut microbiota induced by clinically relevant interventions would impact the bioavailability of dietary amino acids in neonates. We tested the hypothesis that modulation of the gut microbiota in neonatal pigs receiving no treatment (control), intravenously administered antibiotics, or probiotics affects whole body nitrogen and amino acid turnover. We quantified whole body urea kinetics, threonine fluxes, and threonine disposal into protein, oxidation, and tissue protein synthesis with stable isotope techniques. Compared with controls, antibiotics reduced the number and diversity of bacterial species in the distal small intestine (SI) and colon. Antibiotics decreased plasma urea concentrations via decreased urea synthesis. Antibiotics elevated threonine plasma concentrations and turnover, as well as whole body protein synthesis and proteolysis. Antibiotics decreased protein synthesis rate in the proximal SI and liver but did not affect the distal SI, colon, or muscle. Probiotics induced a bifidogenic microbiota and decreased plasma urea concentrations but did not affect whole body threonine or protein metabolism. Probiotics decreased protein synthesis in the proximal SI but not in other tissues. In conclusion, modulation of the gut microbiota by antibiotics and probiotics reduced hepatic ureagenesis and intestinal protein synthesis, but neither altered whole body net threonine balance. These findings suggest that changes in amino acid and nitrogen metabolism resulting from antibiotic- or probiotic-induced shifts in the microbiota are localized to the gut and liver and have limited impact on whole body growth and anabolism in neonatal piglets.

Effect of spaceflight on human protein metabolism

1993 ◽  
Vol 264 (5) ◽  
pp. E824-E828 ◽  
Author(s):  
T. P. Stein ◽  
M. J. Leskiw ◽  
M. D. Schluter
Keyword(s):  
Protein Synthesis ◽  
Nitrogen Balance ◽  
Protein Metabolism ◽  
Space Shuttle ◽  
Single Pulse ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Body Protein ◽  
Space Shuttle Columbia

Nitrogen balance and the whole body protein synthesis rate were measured before, during, and after a 9.5-day spaceflight mission on the space shuttle Columbia. Protein synthesis was measured by the single-pulse [15N]glycine method. Determinations were made 56, 26, and 18 days preflight, on flight days 2 and 8, and on days 0, 6, 14, and 45 postflight. We conclude that nitrogen balance was decreased during spaceflight. The decrease in nitrogen balance was greatest on the 1st day when food intake was reduced and again toward the end of the mission. An approximately 30% increase in protein synthesis above the preflight baseline was found for flight day 8 for all 6 subjects (P < 0.05), indicating that the astronauts showed a stress response to spaceflight.

scholarly journals Increased plasma Gln and Leu Raand inappropriately low muscle protein synthesis rate in AIDS wasting

1998 ◽  
Vol 275 (4) ◽  
pp. E577-E583 ◽  
Author(s):  
Kevin E. Yarasheski ◽  
Jeffrey J. Zachwieja ◽  
Jennifer Gischler ◽  
Jan Crowley ◽  
Mary M. Horgan ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Asymptomatic Group ◽  
Body Protein ◽  
Asymptomatic Subjects ◽  
Muscle Protein Synthesis Rate

Muscle protein wasting occurs in human immunodeficiency virus (HIV)-infected individuals and is often the initial indication of acquired immunodeficiency syndrome (AIDS). Little is known about the alterations in muscle protein metabolism that occur with HIV infection. Nine subjects with AIDS wasting (CD4 < 200/mm3), chronic stable opportunistic infections (OI), and ≥10% weight loss, fourteen HIV-infected men and one woman (CD4 > 200/mm3) without wasting or OI (asymptomatic), and six HIV-seronegative lean men (control) received a constant intravenous infusion of [1-13C]leucine (Leu) and [2-15N]glutamine (Gln). Plasma Leu and Gln rate of appearance (Ra), whole body Leu turnover, disposal and oxidation rates, and [13C]Leu incorporation rate into mixed muscle protein were assessed. Total body muscle mass/fat-free mass was greater in controls (53%) than in AIDS wasting (43%; P = 0.04). Fasting whole body proteolysis and synthesis rates were increased above control in the HIV+ asymptomatic group and in the AIDS-wasting group ( P = 0.009). Whole body Leu oxidation rate was greater in the HIV+ asymptomatic group than in the control and AIDS-wasting groups ( P < 0.05). Fasting mixed muscle protein synthesis rate was increased in the asymptomatic subjects (0.048%/h; P = 0.01) but was similar in AIDS-wasting and control subjects (0.035 vs. 0.037%/h). Plasma Gln Rawas increased in AIDS-wasting subjects but was similar in control and HIV+ asymptomatic subjects ( P < 0.001). These findings suggest that AIDS wasting results from 1) a preferential reduction in muscle protein, 2) a failure to sustain an elevated rate of mixed muscle protein synthesis while whole body protein synthesis is increased, and 3) a significant increase in Gln release into the circulation, probably from muscle. Several interesting explanations for the increased Gln Rain AIDS wasting exist.

Adult Trichostrongylus colubriformis infection did not affect protein synthesis rate in whole-body, intestinal, hepatic and skeletal muscle tissues of lambs fed fresh Lucerne (Medicago sativa)

2007 ◽  
Vol 87 (3) ◽  
pp. 315-325 ◽  
Author(s):  
E. N. Bermingham ◽  
W. C. McNabb ◽  
I. A. Sutherland ◽  
B. R. Sinclair ◽  
B. P. Treloar ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Medicago Sativa ◽  
Parasitic Infection ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Lymphoid Tissues ◽  
Trichostrongylus Colubriformis ◽  
Body Protein

The effects of an established Trichostrongylus colubriformis infection on the whole-body and fractional protein synthesis rates in the small intestine, liver, lymphoid tissues, skeletal muscle and skin were determined in lambs fed fresh Lucerne (Medicago sativa; 800 g DM d-1) on day 48 post-infection. Lambs were dosed with 6000 L3 T. colubriformis larvae for 6 d (n = 5) or kept as parasite-free controls (n = 6). On day 45, the lambs received a bolus injection of deuterated water to measure the size of the whole-body water pool. On day 48, the lambs were continuously infused with [3, 4-3H]-valine into the jugular vein and [1-13C]-valine in the abomasum for 8 h. During the infusion, mesenteric artery blood and terminal tissue samples were collected for measuring the isotopic activity of plasma water, plasma valine, intra cellular valine and protein-bound valine. Intestinal worm numbers on day 48 were higher (P < 0.001) in the infected lambs, however, there was no effect (P > 0.10) of parasitic infection on feed intake, liveweight gain, whole-body protein synthesis and fractional protein synthesis of most tissues. Key words: Parasite infection, protein synthesis, lambs

Whole body and forearm substrate metabolism in hyperthyroidism: evidence of increased basal muscle protein breakdown

2005 ◽  
Vol 288 (6) ◽  
pp. E1067-E1073 ◽  
Author(s):  
Anne Lene Dalkjær Riis ◽  
Jens Otto Lunde Jørgensen ◽  
Signe Gjedde ◽  
Helene Nørrelund ◽  
Anne Grethe Jurik ◽  
...  
Keyword(s):  
Amino Acid ◽  
Muscle Protein ◽  
Clinical Manifestations ◽  
Metabolic Effects ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Protein Breakdown ◽  
Body Protein ◽  
Muscle Protein Breakdown

Thyroid hormones have significant metabolic effects, and muscle wasting and weakness are prominent clinical features of chronic hyperthyroidism. To assess the underlying mechanisms, we examined seven hyperthyroid women with Graves' disease before (Ht) and after (Eut) medical treatment and seven control subjects (Ctr). All subjects underwent a 3-h study in the postabsorptive state. After regional catheterization, protein dynamics of the whole body and of the forearm muscles were measured by amino acid tracer dilution technique using [15N]phenylalanine and [2H4]tyrosine. Before treatment, triiodothyronine was elevated (6.6 nmol/l) and whole body protein breakdown was icreased 40%. The net forearm release of phenylalanine was increased in hyperthyroidism (μg·100 ml−1·min−1): −7.0 ± 1.2 Ht vs. −3.8 ± 0.8 Eut ( P = 0.04), −4.2 ± 0.3 Ctr ( P = 0.048). Muscle protein breakdown, assessed by phenylalanine rate of appearance, was increased (μg·100 ml−1·min−1): 15.5 ± 2.0 Ht vs. 9.6 ± 1.4 Eut ( P = 0.03), 9.9 ± 0.6 Ctr ( P = 0.02). Muscle protein synthesis rate did not differ significantly. Muscle mass and muscle function were decreased 10–20% before treatment. All abnormalities were normalized after therapy. In conclusion, our results show that hyperthyroidism is associated with increased muscle amino acid release resulting from increased muscle protein breakdown. These abnormalities can explain the clinical manifestations of sarcopenia and myopathy.

scholarly journals Effect of dietary tryptophan on muscle, liver and whole-body protein synthesis in weaned piglets: relationship to plasma insulin

1991 ◽  
Vol 66 (3) ◽  
pp. 423-435 ◽  
Author(s):  
N. O. Cortamira ◽  
B. Seve ◽  
Y. Lebreton ◽  
P. Ganier
Keyword(s):  
Protein Synthesis ◽  
Growth Performance ◽  
Plasma Insulin ◽  
Live Weight ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Liver Protein ◽  
Deficient Diet ◽  
Body Protein

Two experiments were carried out with piglets, 3–5 kg live weight, to evaluate the effects of feeding a tryptophan (TRP)-deficient diet for 2 weeks on protein synthesis rates measured in vivo 2 h after a meal. In the first experiment on twenty piglets fed on 250 g protein/kg diets, TRP deficiency (0.77 g/16 g nitrogen) as compared with adequacy (1.17 g/16 g N) significantly decreased feed intake, growth performance and fractional protein synthesis rates (FSR), without variation of RNA in longissimus dorsi (LD) and with parallel increases in RNA in semitendinosus (ST) muscle and liver. In the second experiment thirty-two piglets were tube-fed deficient and adequate diets at the two feeding levels (LF) previously achieved. Both TRP and LF significantly increased growth performance and FSR, but not RNA, in LD and ST muscle, with a trend to a synergy between the two factors (TRP x LF interaction). In another muscle, trapezius (TR), the same interaction was only apparent in RNA content. Among the three muscles it was in LD that FSR was the most responsive to dietary TRP (significant muscle x TRP interaction). In the liver the TRP x LF interaction on FSR and not RNA was the major significant effect, indicating that higher TRP and higher LF were both required to get the maximum protein synthesis rate. At 30 min after a meal the same significant interaction effect was shown on plasma glucose, whilst the higher LF increased plasma insulin with both diets. After a further 30 min the appearance of a similar significant effect of the TRP x LF interaction on plasma insulin resulted from its abatement when the deficient diet had been fed at high LF. These results suggest that dietary TRP deficiency decreased muscle and liver protein synthesis rates in relation to a decrease in the post-prandial release of insulin following a decreased rate of nutrient absorption.

Effect of growth hormone and resistance exercise on muscle growth in young men

1992 ◽  
Vol 262 (3) ◽  
pp. E261-E267 ◽  
Author(s):  
K. E. Yarasheski ◽  
J. A. Campbell ◽  
K. Smith ◽  
M. J. Rennie ◽  
J. O. Holloszy ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Resistance Training ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Treated Group ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Body Protein

The purpose of this study was to determine whether growth hormone (GH) administration enhances the muscle anabolism associated with heavy-resistance exercise. Sixteen men (21-34 yr) were assigned randomly to a resistance training plus GH group (n = 7) or to a resistance training plus placebo group (n = 9). For 12 wk, both groups trained all major muscle groups in an identical fashion while receiving 40 micrograms recombinant human GH.kg-1.day-1 or placebo. Fat-free mass (FFM) and total body water increased (P less than 0.05) in both groups but more (P less than 0.01) in the GH recipients. Whole body protein synthesis rate increased more (P less than 0.03), and whole body protein balance was greater (P = 0.01) in the GH-treated group, but quadriceps muscle protein synthesis rate, torso and limb circumferences, and muscle strength did not increase more in the GH-treated group. In the young men studied, resistance exercise with or without GH resulted in similar increments in muscle size, strength, and muscle protein synthesis, indicating that 1) the larger increase in FFM with GH treatment was probably due to an increase in lean tissue other than skeletal muscle and 2) resistance training supplemented with GH did not further enhance muscle anabolism and function.

Albumin and fibrinogen syntheses increase while muscle protein synthesis decreases in head-injured patients

1997 ◽  
Vol 273 (5) ◽  
pp. E898-E902 ◽  
Author(s):  
Odile Mansoor ◽  
Marc Cayol ◽  
Pierre Gachon ◽  
Yves Boirie ◽  
Pierre Schoeffler ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Albumin Synthesis ◽  
Body Protein ◽  
Head Injured ◽  
Injured Patients

The effect of trauma on protein metabolism was investigated in the whole body, muscle, and liver in severely head-injured patients presenting an acute inflammatory response by comparison to fed control subjects receiving a similar diet. Nonoxidative leucine disposal (an index of whole body protein synthesis) and muscle, albumin, and fibrinogen synthesis were determined by means of a primed, continuous infusion ofl-[1-13C]leucine. Nonoxidative leucine disposal increased by 28% in the patients ( P < 0.02). Fractional muscle protein synthesis rate decreased by 50% ( P < 0.01) after injury. Fractional and absolute fribrinogen synthesis rates were multiplied by two and nine, respectively, after injury ( P< 0.001). Albumin levels were lower in patients (25.2 ± 1.2 g/l, means ± SE) than in controls (33.7 ± 1.2 g/l, P < 0.001). However, fractional albumin synthesis rates were increased by 60% in patients (11.4 ± 1.0%/day) compared with controls (7.3 ± 0.4%/day, P < 0.01). Therefore, 1) head trauma induces opposite and large changes of protein synthesis in muscle and acute-phase hepatic proteins, probably mediated by cytokines, glucocorticoids, and other stress hormones, and 2) in these patients, hypoalbuminemia is not due to a depressed albumin synthesis.

Effect of testosterone on muscle mass and muscle protein synthesis

1989 ◽  
Vol 66 (1) ◽  
pp. 498-503 ◽  
Author(s):  
R. C. Griggs ◽  
W. Kingston ◽  
R. F. Jozefowicz ◽  
B. E. Herr ◽  
G. Forbes ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Muscle Mass ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Total Body Potassium ◽  
Body Protein ◽  
Total Body

We have studied the effect of a pharmacological dose of testosterone enanthate (3 mg.kg-1.wk-1 for 12 wk) on muscle mass and total-body potassium and on whole-body and muscle protein synthesis in normal male subjects. Muscle mass estimated by creatinine excretion increased in all nine subjects (20% mean increase, P less than 0.02); total body potassium mass estimated by 40K counting increased in all subjects (12% mean increase, P less than 0.0001). In four subjects, a primed continuous infusion protocol with L-[1–13C]leucine was used to determine whole-body leucine flux and oxidation. Whole-body protein synthesis was estimated from nonoxidative flux. Muscle protein synthesis rate was determined by measuring [13C]leucine incorporation into muscle samples obtained by needle biopsy. Testosterone increased muscle protein synthesis in all subjects (27% mean increase, P less than 0.05). Leucine oxidation decreased slightly (17% mean decrease, P less than 0.01), but whole-body protein synthesis did not change significantly. Muscle morphometry showed no significant increase in muscle fiber diameter. These studies suggest that testosterone increases muscle mass by increasing muscle protein synthesis.

Measurement of protein synthesis rates with [15N]glycine

1980 ◽  
Vol 239 (4) ◽  
pp. E294-E294 ◽  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Free Amino Acids ◽  
Free Amino ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Liver Protein ◽  
Body Protein ◽  
15N Enrichment

[15N]glycine (95+%) was infused into 170- to 220-g rats at a constant rate of 2-8 mg [15N]glycine/h for 2-24 h. Two sets of experiments were done. In one set, the rats were killed at varying time intervals, the liver was removed, and the fractional rate of liver protein synthesis was estimated from the amount of 15N incorporated into liver protein, the enrichment of the liver tissue free amino nitrogen, and the time course. In the second set of experiments, the rats were killed after a [15N]glycine infusion of 18-22 h. The whole-body protein synthesis rate was estimated from the urinary 15N enrichment at plateau by the method of Picou and Taylor-Roberts (Clin. Sci. 36: 288-296, 1967). It was compared against the value found by measuring the 15N enrichment of the whole-rat homogenate and calculating the synthesis rate from the formula of Garlick et al. [Biochem. J. 136: 935-945, 1973). The results are i) The 15N enrichment of glycine in either liver protein or liver tissue free amino acids was proportional to the 15N enrichment of the mixed protein or tissue free amino acids, respectively. ii) Continuous infusion-isotopic plateau methods underestimate the fractional protein synthesis rate of rat liver. iii) The methods of Picou and Taylor-Roberts and of Garlick et al. gave similar values for the whole-body protein synthesis rate.

Increased tissue protein synthesis during spontaneous inflammatory bowel disease in HLA-B27 rats

2003 ◽  
Vol 105 (4) ◽  
pp. 437-446 ◽  
Author(s):  
Mimoun EL YOUSFI ◽  
Denis BREUILLÉ ◽  
Isabelle PAPET ◽  
Stéphanie BLUM ◽  
Marc ANDRÉ ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Hla B27 ◽  
Metabolic Disturbances ◽  
Drug Induced ◽  
Body Protein ◽  
Inflammatory Bowel ◽  
Different Tissues

Inflammatory bowel diseases (IBDs) are associated with an increased whole-body protein turnover. In certain drug-induced experimental models of IBD, disturbances of protein synthesis in tissues have been reported recently, but it is unclear if similar disturbances occur in other chronic intestinal diseases. Therefore we investigated changes in protein synthesis in different tissues of HLA-B27 (human leucocyte antigen B27) transgenic rats that develop spontaneously chronic inflammation, with major involvement of the colon. Protein synthesis rate in HLA-B27 rats was shown to be higher in nine different tissues compared with control (Fisher 344) rats. The absolute rate of protein synthesis was highly stimulated at the main inflammatory site (+290% in the colon). However, liver, muscle and skin appeared to be major contributors to the increased protein synthesis observed at the whole-body level. Despite the increased protein synthesis, HLA-B27 rats presented a marked atrophy of muscles, which suggests an increased proteolysis. These results contrast with metabolic disturbances described in acute inflammation and colitis induced by drugs (i.e. dextran sodium sulphate). The present study suggests that the modifications of protein metabolism are strongly influenced by the type of the inflammatory diseases and thus by the underlying mechanisms, which result in different metabolic adaptations and specific nutritional requirements.

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