scholarly journals Whole body and tissue fractional protein synthesis in the ovine fetusin utero

1984 ◽  
Vol 52 (2) ◽  
pp. 359-369 ◽  
Author(s):  
A. L. Schaefer ◽  
C. R. Krishnamurti
Keyword(s):  
Protein Synthesis ◽  
Activity Ratio ◽  
Specific Activity ◽  
Whole Body ◽  
Absolute Rate ◽  
Body Protein ◽  
Tissue Protein ◽  
Fractional Rate ◽  
Tyrosine Concentration

1. Whole-body and tissue fractional protein synthesis rates were determined in chronically-catheterized ovine fetuses at 120–130 d of gestation following an 8 h continuous infusion of L-[U-14C]-or L-[2, 3, 5, 6-3H]tyrosine.2. From the net utilization of tyrosine by the fetus, corrected for apparent oxidation, and tyrosine concentration in the fetal carcass protein, whole-body protein synthesis was estimated to be 63 g/d per kg.3. Following 8 h of infusion of labelled tyrosine the ewes were killed and fetal tissues were removed for the determination of tyrosine specific activity. The fractional rate of protein synthesis (k3) was calculated from the specific activity ratio, protein bound: intracellular free tyrosine. Tissue k, values for the liver, kidney, lungs, brain, skeletal muscle and small intestine were 78, 45, 65, 37, 26 and 93% /d respectively.4. The absolute rate of synthesis was calculated by multiplying the tissue protein content by k2. Muscles, gastrointestinal tract, liver and lungs contributed approximately 20.5, 20.5, 14.4 and 9.4% respectively to whole- body protein synthesis.5. The efficiency of protein synthesis as expressed by the RNA activity was higher in liver, lung and brain followed by kidney, skeletal and cardiac muscle.

Effect of dietary protein and energy intakes on whole-body protein turnover and its contribution to heat production in chicks

1993 ◽  
Vol 69 (3) ◽  
pp. 681-688 ◽  
Author(s):  
K. Kita ◽  
T. Muramatsu ◽  
J. Okumura
Keyword(s):  
Protein Synthesis ◽  
Heat Production ◽  
Protein Turnover ◽  
Crude Protein ◽  
Total Heat ◽  
Interactive Effects ◽  
Whole Body ◽  
Small Range ◽  
Body Protein ◽  
Fractional Rate

A factorial 3 × 3 experiment was conducted with chicks to investigate the effect of manipulating crude protein (N × 6.25) intake (CPI) and metabolizable energyintake (MEI) simultaneously, in the range low to high (including adequate) levels with regard to the respective requirements, on whole-body protein turnover and its contribution to total heat production. The fractional rate of whole-body protein synthesis was increased curvilinearly by increasing MEI or CPI from low to high levels. In terms of absolute rates whole-body protein synthesis was enhanced by increasing MEI from low to adequate levels, the effect being greater at adequate and high CPI than at low CPI. The effect of varying CPI and MEI on whole-body protein degradation was similar, but less sensitive, to that on whole-body protein synthesis. Increasing MEI from low to high levels elevated totalheat production at all CPI levels. There were no interactive effects of varying CPI andMEI on the contribution of whole-body protein synthesis to total heat production, and in general the contribution increased with increasing CPI and decreased with increasing MEI.The contribution of whole-body protein synthesis to total heat production fell within a small range from 11.2 to 16.5%.

scholarly journals Protein synthesis in tissues of growing lambs

1981 ◽  
Vol 46 (3) ◽  
pp. 409-419 ◽  
Author(s):  
S. R. Davis ◽  
T. N. Barry ◽  
G. A. Hughson
Keyword(s):  
Protein Synthesis ◽  
Cardiac Muscle ◽  
Specific Radioactivity ◽  
Biceps Femoris ◽  
Whole Body ◽  
Tissue Homogenate ◽  
Body Protein ◽  
Tissue Protein ◽  
Biceps Femoris Muscle ◽  
Plasma Leucine

1. The fractional rate of protein synthesis (FSR) in tissues of nine growing lambs (4–5 months of age) was estimated following continuous infusion of L-[4,5–3H]leucine for a period of 7 h. Minimum and upper estimates of FSR were obtained assuming that the specific radioactivity (SRA) of leucine in blood plasma and tissue homogenate respectively defined that of leucyl tRNA.2. Mean upper estimates of tissue protein FSR (/d) were skin 0·35, longissimus dorsi muscle 0·05, biceps femoris muscle 0·04, liver 0·54, rumen 0·79, cardiac muscle 0·09. Minimum estimates of tissue protein FSR ranged from 0·03 (muscle) to 0·15 (liver).3. Plasma leucine flux was closely related to body protein content and dietary leucine absorption (r 0·94).4. The rate of whole-body protein synthesis (WBS) derived from plasma leucine flux corrected for oxidation and localized recycling of leucine into protein was similar to that calculated from the sum of daily protein synthesis in individual tissues using the upper estimate of FSR, i.e. 610 g/d v. 581 g/d.5. The estimate of WBS derived from plasma leucine flux directly (241 g/d) was similar to that calculated from the sum of minimum estimates of daily protein synthesis in individual tissues (214 g/d).6. The ratio, intracellular leucine SRA:plasma leucine SRA tended to increase with increasing dietary leucine absorption in all tissues although these factors were only significantly correlated (P < 0·05) in cardiac muscle, skin and rumen. Such relationships suggest an increased exchange of plasma leucine with intracellular leucine with increased food intake.7. It was estimated that the energy cost of protein synthesis accounted for approximately 42% of daily heat production.

scholarly journals Contribution of liver, skin and skeletal muscle to whole-body protein synthesis in the young lamb

1988 ◽  
Vol 60 (1) ◽  
pp. 77-84 ◽  
Author(s):  
D. Attaix ◽  
E. Aurousseau ◽  
A. Manghebati ◽  
M. Arnal
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Specific Radioactivity ◽  
Whole Body ◽  
Tissue Homogenate ◽  
Synthesis Rate ◽  
Body Protein ◽  
Tissue Protein ◽  
Large Injection ◽  
Tensor Fasciae Latae

1. Protein fractional synthesis rate (FSR) was measured in some major tissues and in the whole body of six 1-week-old sucking lambs by a large injection of L-[3H]valine.2. Upper estimates of tissue protein FSR (%/d), assuming that the tissue-homogenate free-valine specific radioactivity defined that of valyl tRNA, were 115.0 in liver, 24.1 in skin, 22.9 in the white M. tensor fasciae latae, 21.6 in the red M. diaphragma and 19–6 in the remainder (exsanguinated whole body without liver and gastrointestinal tract) of lambs.3. Absolute synthesis rates (ASR) of tissue protein were 17, 19 and 42 g/d in the liver, skin and skeletal muscle respectively, and 112 g/d in the remainder. The ASR of whole-body protein, derived from the tissue values, was 146 g/d, i.e. 33 g/d per kg body-weight. The calculated whole-body protein FSR was 23.9 %/d.4. The relative percentage contribution of liver, skin and skeletal muscle to whole-body protein synthesis was 11.7, 13.1, and 29.0.5. We concluded that tissue protein FSR in lambs were in exactly the same decreasing order, from visceral tissues to skeletal muscles, as observed in rats. The ovine FSR estimates and the partitioning of protein synthesis between tissues were in the same range as values recently obtained by flooding-dose experiments in immature rats, piglets, and even in chicks. These findings suggest that inter-species differences are rather limited.

scholarly journals Protein synthesis and growth in the gastrointestinal tract of the young preruminant lamb

1987 ◽  
Vol 58 (1) ◽  
pp. 159-169 ◽  
Author(s):  
D. Attaix ◽  
M. Arnal
Keyword(s):  
Protein Synthesis ◽  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Specific Radioactivity ◽  
Whole Body ◽  
Tissue Homogenate ◽  
Body Protein ◽  
Tissue Protein ◽  
Precursor Pool ◽  
Gastrointestinal Tissue

1. In Expt 1, fractional synthesis rates (FSR) of tissue protein were measured along the gastrointestinal tract (GIT) of six 1-week-old, milk-fed lambs by using a large amount of L-[3,4(n)-3H]valine.2. In Expt 2, eighteen lambs were used to determine the fractional growth rate (FGR) of gastrointestinal tissue protein.3. FSRMinimum(Min) and FSRMaximum(Max) were calculated assuming plasma or tissue homogenate free valine specific radioactivity was representative of the valine precursor pool for protein synthesis. There were no significant differences between FSR(Min) and FSR(Max) in any gastrointestinal tissue of lambs used in Expt 1 (P > 0.05). FSR gradually and significantly (P > 0.05) increased from the oesophagus (FSR(Max)26.5%/d). reticulo-rumen (30.1%/d), omasum (41.0%/d) and abomasum (56.1%/d) to small intestine (87.5%/d), and then declined significantly (P < 0.05) towards the caecum (45.2%/d) and the colon (38.4%/d). No significant differences were observed between FSR in the duodenum, jejunum or ileum (P > 0.05).4. FGR ranged from 2,6%/d in the oesophagus to 8,7%/d in the omasum. The ratio, FGR:FSR, which reflected the efficiency of protein deposition, was at a maximum in the stomachs and caecum and at a minimum in the small intestine.5. The relative contribution of the oesophagus, stomachs, small intestine and large intestine to GIT protein synthesis was 1, 13, 76 and 10% respectively. The GIT accounted for approximately 11.5% of whole-body protein synthesis.

Postprandial myofibrillar and whole body protein synthesis in young and old human subjects

1994 ◽  
Vol 267 (4) ◽  
pp. E599-E604 ◽  
Author(s):  
S. Welle ◽  
C. Thornton ◽  
M. Statt ◽  
B. McHenry
Keyword(s):  
Protein Synthesis ◽  
Lean Body Mass ◽  
Body Mass ◽  
Human Subjects ◽  
Vastus Lateralis ◽  
Whole Body ◽  
Vastus Lateralis Muscle ◽  
Body Protein ◽  
Creatinine Excretion ◽  
Fractional Rate

Rates of incorporation of leucine (using L-[1-13C]leucine as a tracer) into myofibrillar and whole body proteins were determined in healthy old (> 60 yr old, n = 7) and young (< 30 yr old, n = 9) men and women who were fed small meals (4% of daily energy) every 30 min. There was no difference in whole body incorporation of leucine into proteins in the young (148 +/- 5 mumol.h-1.kg lean body mass-1, means +/- SE) and old groups (150 +/- 3 mumol.h-1.kg lean body mass-1). However, the fractional myofibrillar protein synthesis in the vastus lateralis muscle was 28% slower in the older group (0.063 +/- 0.004 vs. 0.088 +/- 0.003 %/h, P < 0.001). Extrapolation of these results to whole body myofibrillar synthesis (fractional rate x myofibrillar mass estimated by creatinine excretion) indicated that, in the older group, total myofibrillar synthesis was 43% slower (1.8 +/- 0.2 vs. 3.1 +/- 0.2 g/h, P < 0.01) and that their myofibrillar synthesis was a smaller portion of whole body protein synthesis (15 +/- 1 vs. 23 +/- 1%, P < 0.001). Compared with age-matched postabsorptive subjects, whole body protein synthesis was approximately 25% faster, and fractional myofibrillar synthesis was approximately 50% faster in these fed subjects, both young and old. We conclude that myofibrillar synthesis is slower in older subjects during both postabsorptive and postprandial conditions but that aging does not impair the stimulatory effect of feeding on protein synthesis.

Whole-body and tissue protein synthesis during brief and prolonged fasting in the rat

1991 ◽  
Vol 81 (5) ◽  
pp. 611-619 ◽  
Author(s):  
Yves Cherel ◽  
Didier Attaix ◽  
Danuta Rosolowska-Huszcz ◽  
Rajae Belkhou ◽  
Jean-Patrice Robin ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Skeletal Muscles ◽  
Whole Body ◽  
Protein Loss ◽  
Body Protein ◽  
Tissue Protein ◽  
Control Value ◽  
Tissue Protein Synthesis ◽  
Fractional Synthesis

1. Little information is currently available on protein turnover during chronic protein loss situations. We have thus measured the whole-body and tissue protein fractional synthesis rates (ks), the whole-body fractional protein degradation rate (kd), the capacity for protein synthesis (Cs) and the efficiency of protein synthesis (kRNA) in vivo in fed and fasted (1, 5 and about 9 days) 400 g rats. 2. One day of starvation resulted in a reduced ks and an increased kd in the whole body. ks was selectively depressed in skeletal muscles, mainly owing to a reduced kRNA, and was not modified in heart, liver and skin. The contribution of skin to whole-body protein synthesis increased by 39%. 3. During the phase of protein sparing (5 days of fasting), kd in the whole body decreased below the control fed level. ks in skeletal muscles was sustained because kRNA was restored to 82–98% of the control value. 4. Rats were in a protein-wasting phase after 9 days of starvation. kd in the whole body did not increase and was actually 78% of the value observed in fed animals. By contrast, ks in the whole body and tissues decreased to 14–34% of the control values, owing to reductions in both Cs and kRNA. Whatever the duration of the fast, the contribution of the skin to whole-body protein synthesis largely exceeded that of skeletal muscle. 5. The present findings suggest that the main goal in the treatment of chronic protein loss should be to sustain protein synthesis. Our data also emphasize the importance of skin in whole-body protein synthesis in fasting and possibly in other protein loss situations.

Whole-body and tissue protein synthesis in steers losing weight on a low-protein roughage diet: the effect of trenbolone acetate

1990 ◽  
Vol 115 (1) ◽  
pp. 121-127 ◽  
Author(s):  
R. A. Hunter ◽  
T. Magner
Keyword(s):  
Protein Synthesis ◽  
Bos Indicus ◽  
Nitrogen Retention ◽  
Live Weight ◽  
Whole Body ◽  
Body Protein ◽  
Trenbolone Acetate ◽  
Fractional Rate ◽  
Low Protein ◽  
Tissue Protein Synthesis

SUMMARYSix Brahman (Bos indicus) steers implanted with 300 mg trenbolone acetate and six similar nonimplanted steers were fed a low-quality, low-protein roughage diet at 10 g dry matter/kg live weight. They were housed in individual pens for 27 days in 1987 before being placed in metabolism crates for measurement of digestibility, nitrogen retention, and the rate of protein synthesis in the whole body and fractional rate in three muscles and hide.The rate of weight loss of steers treated with trenbolone acetate was significantly (P < 0·05) less than that of controls (–0·34 v. –0·56 kg/day). Treated steers excreted significantly (P < 0·05) less 3-methylhistidine (128 v. 202 μmol) and urea N (0·5 v. 1·6 g/day) in urine. There was a more favourable nitrogen retention in animals implanted with trenbolone acetate (–10 v. –12g/day) but this difference was not significant.Whole-body protein synthesis, calculated from plasma leucine flux, was 511 and 508 g/day in treated and control steers, respectively. Treatment also had no significant effect on the fractional rate of protein synthesis, in skeletal muscle or in hide. The fractional rate of synthesis in muscle was < 1%/day and in hide < 2%/day. These results are discussed in relation to the protein and energy metabolism of undernourished cattle.

Short-term growth hormone treatment does not increase muscle protein synthesis in experienced weight lifters

1993 ◽  
Vol 74 (6) ◽  
pp. 3073-3076 ◽  
Author(s):  
K. E. Yarasheski ◽  
J. J. Zachweija ◽  
T. J. Angelopoulos ◽  
D. M. Bier
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Protein Breakdown ◽  
Short Term ◽  
Body Protein ◽  
Fractional Rate ◽  
Weight Lifters

The purpose of this study was to determine whether recombinant human growth hormone (GH) administration enhances muscle protein anabolism in experienced weight lifters. The fractional rate of skeletal muscle protein synthesis and the whole body rate of protein breakdown were determined during a constant intravenous infusion of [13C]leucine in 7 young (23 +/- 2 yr; 86.2 +/- 4.6 kg) healthy experienced male weight lifters before and at the end of 14 days of subcutaneous GH administration (40 microgram.kg-1 x day-1). GH administration increased fasting serum insulin-like growth factor-I (from 224 +/- 20 to 589 +/- 80 ng/ml, P = 0.002) but did not increase the fractional rate of muscle protein synthesis (from 0.034 +/- 0.004 to 0.034 +/- 0.002%/h) or reduce the rate of whole body protein breakdown (from 103 +/- 4 to 108 +/- 5 mumol.kg-1 x h-1). These findings suggest that short-term GH treatment does not increase the rate of muscle protein synthesis or reduce the rate of whole body protein breakdown, metabolic alterations that would promote muscle protein anabolism in experienced weight lifters attempting to further increase muscle mass.

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.

Sign in / Sign up

Export Citation Format

Share Document