Muscle Protein Degradation in Premature Human Infants

1979 ◽  
Vol 57 (6) ◽  
pp. 535-544 ◽  
Author(s):  
F. J. Ballard ◽  
F. M. Tomas ◽  
L. M. Pope ◽  
P. G. Hendry ◽  
B. E. James ◽  
...  
Keyword(s):  
Protein Degradation ◽  
Premature Infants ◽  
Muscle Protein ◽  
Myofibrillar Protein ◽  
Human Beings ◽  
Protein Breakdown ◽  
Human Infants ◽  
Balance Study ◽  
Muscle Protein Degradation ◽  
Total Muscle

1. Myofibrillar protein degradation has been measured by the rate of 3-methylhistidine excretion in premature infants weighing between 635 g and 1295 g. Analyses were made in conjunction with 1–3 day nitrogen balance studies. 2. In 56 balance studies in 36 infants, total muscle protein breakdown varied between 0·70 and 2·58 (mean 1·05) g day−1 kg−1 body weight while the percentage of total muscle protein degraded each day was between 3·3 and 8·3 (mean 4·8). 3. Both total and fractional rates of protein breakdown showed highly significant negative correlations with nitrogen retention but no relationship to total energy input. 4. Protein degradation was higher than average in infants who were losing weight at the time of the balance study, lower in infants who were gaining weight and higher in those who died within 2 weeks of the analysis. 5. Myofibrillar protein breakdown was not different between infants fed orally and those receiving total parenteral nutrition. 6. Generally the effects of nitrogen and energy status on muscle protein degradation in the premature infants are different from changes reported in adult human beings or adult rats. We suggest that this difference may be a consequence of the very limited energy reserves of the premature infant.

A reexamination of the effect of exercise on rate of muscle protein degradation

2006 ◽  
Vol 263 (6) ◽  
pp. E1144-E1150 ◽  
Author(s):  
G. J. Kasperek ◽  
G. R. Conway ◽  
D. S. Krayeski ◽  
J. J. Lohne
Keyword(s):  
Skeletal Muscle ◽  
Protein Degradation ◽  
Total Protein ◽  
Food Restriction ◽  
Muscle Protein ◽  
Recovery Period ◽  
Lower Leg ◽  
Myofibrillar Protein ◽  
Rat Skeletal Muscle ◽  
Muscle Protein Degradation

The purpose of this study was to examine the effect of exercise on the rate of protein degradation in rat skeletal muscle. The rates of total and myofibrillar protein degradation were determined by the measurement of the rates of release of tyrosine and 3-methylhistidine, respectively, from the perfused single rat leg. This method measures the rate of protein degradation in the entire lower leg and does not suffer from the limitations inherent in methods that rely on urinary excretion. The rate of total protein degradation was increased by exercise and involved increased flux through the lysosomal pathway, while the breakdown of myofibrillar protein was unchanged. The changes in the rates of protein degradation during the recovery period were greatly influenced by energy intake. Again the rate of myofibrillar protein degradation was unchanged or slightly increased during the recovery period, after either level or downgrade running. Exercise did prevent the increase in the rate of total protein degradation caused by food restriction, which may have important implications in weight reduction diets.

Measurement of muscle protein degradation in live mice by accumulation of bestatin-induced peptides

1997 ◽  
Vol 273 (6) ◽  
pp. E1149-E1157 ◽  
Author(s):  
Violeta Botbol ◽  
Oscar A. Scornik
Keyword(s):  
Protein Degradation ◽  
Protein Turnover ◽  
Skeletal Muscles ◽  
Muscle Protein ◽  
Cellular Proteins ◽  
Protein Breakdown ◽  
Maximum Accumulation ◽  
Muscle Protein Breakdown ◽  
Muscle Protein Degradation ◽  
Acute Changes

Bestatin, an aminopeptidase inhibitor, permits the degradation of cellular proteins to di- and tripeptides but interferes with the further breakdown of these peptides to amino acids. We propose to measure instant rates of protein degradation in skeletal muscles of intact mice by the accumulation of bestatin-induced intermediates. Muscle protein was labeled by injection ofl-[guanidino-14C]arginine; 3 days later, maximum accumulation of intermediates was measured in abdominal wall muscles 10 min after the intravenous injection of 5 mg of bestatin. The peptides were partially purified and hydrolyzed in 6 N HCl, and the radioactivity in peptide-derived arginine was determined, after conversion to14CO2by treatment with arginase and urease. The measurement of bestatin-induced intermediates provides a unique tool for studying acute changes in muscle protein turnover in live mice. We observed a 62% increase in muscle protein breakdown after a 16-h fast, which was reversed by refeeding for 3.5 h, and a 38% increase after 3 days of protein depletion.

A reexamination of the effect of exercise on rate of muscle protein degradation

1992 ◽  
Vol 263 (6) ◽  
pp. E1144-E1150 ◽  
Author(s):  
G. J. Kasperek ◽  
G. R. Conway ◽  
D. S. Krayeski ◽  
J. J. Lohne
Keyword(s):  
Skeletal Muscle ◽  
Protein Degradation ◽  
Total Protein ◽  
Food Restriction ◽  
Muscle Protein ◽  
Recovery Period ◽  
Lower Leg ◽  
Myofibrillar Protein ◽  
Rat Skeletal Muscle ◽  
Muscle Protein Degradation

The purpose of this study was to examine the effect of exercise on the rate of protein degradation in rat skeletal muscle. The rates of total and myofibrillar protein degradation were determined by the measurement of the rates of release of tyrosine and 3-methylhistidine, respectively, from the perfused single rat leg. This method measures the rate of protein degradation in the entire lower leg and does not suffer from the limitations inherent in methods that rely on urinary excretion. The rate of total protein degradation was increased by exercise and involved increased flux through the lysosomal pathway, while the breakdown of myofibrillar protein was unchanged. The changes in the rates of protein degradation during the recovery period were greatly influenced by energy intake. Again the rate of myofibrillar protein degradation was unchanged or slightly increased during the recovery period, after either level or downgrade running. Exercise did prevent the increase in the rate of total protein degradation caused by food restriction, which may have important implications in weight reduction diets.

scholarly journals Nitrogen balance and myofibrillar protein turnover in double muscled Belgian Blue bulls in relation to compensatory growth after different periods of restricted feeding

1998 ◽  
Vol 78 (4) ◽  
pp. 549-559 ◽  
Author(s):  
C. Van Eenaeme ◽  
M. Evrard ◽  
J. L. Hornick ◽  
P. Baldwin ◽  
M. Diez ◽  
...  
Keyword(s):  
Nitrogen Balance ◽  
Compensatory Growth ◽  
Muscle Protein ◽  
Growth Period ◽  
Myofibrillar Protein ◽  
Control Group ◽  
Protein Breakdown ◽  
Low Protein ◽  
Fattening Period ◽  
Synthesis And Degradation

Nitrogen balance and myofibrillar protein breakdown were studied in 16 double-muscled Belgian Blue bulls during a low growth period (0.5 kg d−1) (LGP) of 4 mo (L4), 8 mo (L8), or 14 mo (L14) and the subsequent fattening period (rapid growth period, RGP). The control group (CG) was given a conventional fattening diet; the others received a low-energy, low-protein diet during LGP, and the same diet as the CG during RGP. Measurements were made halfway through the LGP, l mo after the beginning of the fattening period, and 1 mo before slaughter. Nitrogen balance was about half of CG (P < 0.001) during LGP, e.g., 50.8, 21.3, 25.8, and 23.8 g d−1, for CG, L4, L8, and L14, respectively. Between LGP and RGP, N balance increased by about 18 g N d−1 above the control in the compensating groups L4, L8 and L14. This was due to the higher digestibility and the higher metabolizability of the nitrogen in the fattening diet. Lower muscle protein accretion during the LGP resulted from decreased synthesis (P < 0.001) and degradation (P < 0.05) compared with the GC. When changing to RGP different evolution patterns were observed in the three formerly restricted groups, e.g. after a short restriction (L4) both synthesis and degradation rose during the RGP but declined towards the end. After a longer restriction (L8 and L14), synthesis and degradation increased and remained high. The magnitude of these increases was inversely proportional to the length of the restriction period. Key words: Belgian Blue bulls, compensatory growth, nitrogen balance, muscle, muscle protein breakdown

Quercetin enhances the antitumor effect of trichostatin A and suppresses muscle wasting in tumor-bearing mice

2018 ◽  
Vol 9 (2) ◽  
pp. 871-879 ◽  
Author(s):  
Shu-Ting Chan ◽  
Cheng-Hung Chuang ◽  
Yi-Chin Lin ◽  
Jiunn-Wang Liao ◽  
Chong-Kuei Lii ◽  
...  
Keyword(s):  
Protein Degradation ◽  
Antitumor Effect ◽  
Muscle Wasting ◽  
Muscle Protein ◽  
Trichostatin A ◽  
Tumor Bearing ◽  
Muscle Protein Degradation

Quercetin prevents TSA-induced muscle wasting by down-regulating FOXO1 mediated muscle protein degradation.

Mechanism of induction of muscle protein degradation by angiotensin II

2006 ◽  
Vol 18 (7) ◽  
pp. 1087-1096 ◽  
Author(s):  
Steven T. Russell ◽  
Stacey M. Wyke ◽  
Michael J. Tisdale
Keyword(s):  
Angiotensin Ii ◽  
Protein Degradation ◽  
Muscle Protein ◽  
Muscle Protein Degradation
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