scholarly journals Responses in tissue protein synthesis to sub- and supra- maintenance intake in young growing sheep: comparison of large-dose and continuous-infusion techniques

1992 ◽  
Vol 68 (2) ◽  
pp. 373-388 ◽  
Author(s):  
G. E. Lobley ◽  
Patricia M. Harris ◽  
Pat A. Skene ◽  
D. Brown ◽  
E. Milne ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Continuous Infusion ◽  
Large Dose ◽  
Venous Blood ◽  
Live Weight ◽  
Tissue Homogenate ◽  
True Rate ◽  
Tissue Protein ◽  
Tissue Protein Synthesis ◽  
Export Protein

In ten lambs (average live weight 33 kg), five offered 300 g/d (approximately 0.6 x maintenance; L) and five 900 g/d (1.8 x maintenance; H), tissue protein synthesis was measured by three procedures simultaneously. The techniques involved continuous infusion of [U-14C]phenylalanine and [1-13C]leucine over 7–8 h followed by a terminal large dose of [15N]phenylalanine during the last 30 or 60 min. Rates of protein synthesis were then calculated based on the free amino acid or oxo-acid isotopic activity in either arterial, iliac venous blood or tissue homogenate for the continuous-infusion studies, or on plasma or tissue homogenate for the large-dose procedure. For muscle (> 99%), and to a lesser extent skin (85–93%), effective flood conditions were achieved with the [15N]phenylalanine but were either not established or maintained for liver and tissues of the gastrointestinal tract (< 50%). The large dose of phenylalanine also caused changes in the concentration and isotopic activity of blood leucine and 4-methyl-2-oxo-pentanoate. Based on the assumption that the large-dose procedure yields the closest value for the true rate of protein synthesis (L 1.97%/d, H 2.85%/d) then, for muscle, only values based on the homogenate as precursor gave comparable results for both leucine (L 1.83%/d, H 3.01%/d) and phenylalanine (L 1.67%/d, H 2.71%/d) continuous infusion. The values based on the arterial or venous amino or oxo-acid were significantly less, more so at the lower intake. In contrast, for skin, a tissue dominated by export protein synthesis, values from the large-dose procedure (L 6.37%/d, H 10.98%/d) were similar to those derived with arterial or venous metabolites as precursor (L 5.23 and 6.93%/d, H 9.98 and 11.71%/d for leucine), but much less than those based on homogenate data. Based on the large-dose technique, protein synthesis increased with intake in muscle (P < 0.001), skin (P = 0.009) and liver (26.7 v. 30.5%/d; P = 0.029). The contributions of muscle and skin to total protein synthesis were approximately equal. The incremental efficiency of conversion for muscle of synthesized protein into deposition appeared to be similar to values reported for rodents

Interactions of deoxynivalenol and lipopolysaccharides on tissue protein synthesis in pigs

2013 ◽  
Vol 6 (2) ◽  
pp. 185-197 ◽  
Author(s):  
K. Kullik ◽  
B. Brosig ◽  
S. Kersten ◽  
H. Valenta ◽  
A.-K. Diesing ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Small Intestine ◽  
Control Diet ◽  
Live Weight ◽  
The Body ◽  
Tissue Protein ◽  
Fusarium Toxin ◽  
Synthesis Parameters ◽  
Tissue Protein Synthesis

Possible interactions between the Fusarium toxin deoxynivalenol and lipopolysaccharides on in vivo protein synthesis were investigated in selected porcine tissues. A total of 36 male castrated pigs (initial weight of 26 kg) were used. 24 pigs were fed a control diet and 12 a Fusarium-contaminated diet (chronic oral deoxynivalenol, 3.1 mg/kg diet) for 37 days. Tissue protein synthesis was measured in pigs fed control diet after intravenous infusion of deoxynivalenol (100 µg/kg live weight/h), lipopolysaccharides (7.5 µg/kg live weight/h) or a combination of both compounds on the day of the measurements, while six pigs from the chronic oral deoxynivalenol group were intravenously treated with lipopolysaccharides (7.5 µg/kg live weight/h). Deoxynivalenol challenge alone failed to alter protein synthesis parameters. Fractional protein synthesis rates were exclusively reduced in liver, spleen and small intestine of lipopolysaccharides-treated pigs. Intravenous deoxynivalenol co-exposure enhanced the impacts of lipopolysaccharides on protein synthesis parameters in the spleen and the small intestine to some extent, while a chronic oral pre-exposure with deoxynivalenol relieved its effects in the spleen. Whether these interactions occur in other tissues and under other study conditions, especially toxin doses and route of entry into the body, needs to be examined further.

Measurement of human tissue protein synthesis: an optimal approach

1994 ◽  
Vol 266 (3) ◽  
pp. E298-E307 ◽  
Author(s):  
M. J. Rennie ◽  
K. Smith ◽  
P. W. Watt
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Continuous Infusion ◽  
Human Tissue ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Skeletal Muscle Protein ◽  
Tissue Protein ◽  
Tissue Protein Synthesis

This paper reviews the evidence for and against the adoption of methods for the measurement of human tissue protein synthesis based upon the incorporation of stable isotopically labeled amino acids administered either as a continuous infusion or as a flooding dose. The practical advantages of the flooding dose method are the relative ease of application of the tracer and the ability to make a repeat measurement within approximately 2 h. For the method depending upon continuous infusion of labeled amino acid, the advantages include the use of labeled amino acids at true tracer doses (i.e., with no disturbance of metabolism) and the ability to make simultaneous measurements of whole body turnover and limb or organ turnover (given appropriate sampling techniques). The crucial question concerning the accuracy of the two methods (e.g., the 2-fold difference in the rate of skeletal muscle protein synthesis) remains unresolved, but in our opinion more evidence exists in favor of the values obtained from the continuous infusion method. Furthermore, as techniques for measurement of stable isotopically labelled amino acids improve, the length of time necessary for tracer infusion will fall, and the practical advantages of the flooding dose protocol will lessen in comparison.

scholarly journals Whole body and tissue protein synthesis in cattle

1980 ◽  
Vol 43 (3) ◽  
pp. 491-502 ◽  
Author(s):  
G. E. Lobley ◽  
Vivien Milne ◽  
Joan M. Lovie ◽  
P. J. Reeds ◽  
K. Pennie
Keyword(s):  
Protein Synthesis ◽  
Total Synthesis ◽  
Total Protein ◽  
Specific Radioactivity ◽  
Live Weight ◽  
Whole Body ◽  
Tissue Homogenate ◽  
Body Protein ◽  
Tissue Protein ◽  
The Individual

The daily rates of synthesis of protein by the whole body and by the individual tissues were determined in two Hereford × Friesian heifers (236 kg and 263 kg live weight), and a dry Friesian cow (628 kg live weight).The rate of whole-body protein synthesis (g protein/d) was estimated from the total flux through the blood of [3H]leucine and [3H]tyrosine following infusion at a constant rate for 8 h.The fractional rates of protein synthesis (ks) in the tissues (g synthesized/d per g tissue protein) were obtained after slaughter of the animals at the end of the infusion period. The fractional rate of protein synthesis was calculated assuming that the specific radioactivity of free tyrosine in either the blood (to giveks, b) or the tissue homogenate (to giveks, h) defined closely the specific radioactivity of the amino acid precursor for protein synthesis. Total protein synthesis (As, borAs, h; g/d) in an individual tissue was calculated as the product ofks, b) (orks, h) × protein content.Based on the total leucine flux, i.e. without correction for oxidation, 1.6 kg protein were synthesized daily in the heifers; for the cow this value was 2.0 kg/d.The sum of the daily total synthesis in the major tissues (muscle+bone+brain, gastrointestinal tract (GIT), liver, hide) gave values of 1.4–1.9 kg/d based onAs, b, and 2.2–3.0 kg/d based onAs, h.The percentage contributions of the individual tissues to the total protein synthesis were similar in all three animals, for example based onAs, hmuscle was 12–16; carcass (muscle+bone+brain) 32–33; GIT 38–46; liver 7–8; skin 14–21%.The contribution of muscle to total synthesis estimated from the leucine flux was 19–22%; this value is in agreement with those calculated on the same basis for other species.The energy cost of protein synthesis was estimated to account for a maximum of 30% of heat production.

scholarly journals Tissue protein synthesis and nucleic acid concentrations in steers treated with somatotropin

1989 ◽  
Vol 62 (3) ◽  
pp. 657-671 ◽  
Author(s):  
J. H. Eisemann ◽  
A. C. Hammond ◽  
T. S. Rumsey
Keyword(s):  
Protein Synthesis ◽  
Small Intestine ◽  
Nucleic Acid ◽  
Specific Radioactivity ◽  
Whole Body ◽  
Tissue Homogenate ◽  
Synthesis Rate ◽  
Body Protein ◽  
Tissue Protein ◽  
Tissue Protein Synthesis

The effect of injection with bovine somatotropin (bST) on the fractional rate of protein synthesis (FSR) in tissues of beef steers was studied using a continuous infusion of [1-14C]leucine. Minimum and maximum FSR were calculated from free leucine specific radioactivity (SRA) in plasma or tissue homogenate respectively. Tissue nucleic acid concentrations were also quantified. Tissue samples were obtained from several muscles, sections of the small intestine and liver. In response to bST, both minimum and maximum FSR increased in muscle but not liver or intestinal tissues. Absolute synthesis rate increased in several muscles and small intestine tissues. Treatment with bST increased the relative SRA of protein-bound leucine in muscles compared with liver; increased the amount of protein synthesis per unit empty body-weight (EBW) in most muscles; and increased weight of small intestine relative to EBW, suggesting a differential response between liver and the other tissues measured. Compositional changes in response to bST occurred only in muscles. DNA concentration increased while protein:DNA decreased in the gastrocnemius muscle and RNA:DNA increased in the longissimus dorsi. The maximum percentage contribution of tissue protein synthesis to whole-body protein synthesis was 12·6, 25·7 and 20·5, and 13·0, 29·4 and 25·8 for liver, muscle, and small intestine in placebo-treated and bST-injected steers respectively.

scholarly journals Dietary Ornithine Affects the Tissue Protein Synthesis Rate in Young Rats

2012 ◽  
Vol 58 (4) ◽  
pp. 297-302 ◽  
Author(s):  
Kazuyo TUJIOKA ◽  
Takashi YAMADA ◽  
Mami AOKI ◽  
Koji MORISHITA ◽  
Kazutoshi HAYASE ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Tissue Protein ◽  
Young Rats ◽  
Tissue Protein Synthesis

Effects of the Fusarium toxin deoxynivalenol on tissue protein synthesis in pigs

2006 ◽  
Vol 165 (3) ◽  
pp. 297-311 ◽  
Author(s):  
S DANICKE ◽  
T GOYARTS ◽  
S DOLL ◽  
N GROVE ◽  
M SPOLDERS ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Tissue Protein ◽  
Fusarium Toxin ◽  
Tissue Protein Synthesis

Methionine Flux and Tissue Protein Synthesis in Lactating and Dry Goats

1990 ◽  
Vol 120 (9) ◽  
pp. 1006-1015 ◽  
Author(s):  
Claude Champredon ◽  
Elisabeth Debras ◽  
Philippe Patureau Mirand ◽  
Maurice Arnal
Keyword(s):  
Protein Synthesis ◽  
Tissue Protein ◽  
Tissue Protein Synthesis
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