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.

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.

Mechanism for the increased skeletal muscle protein degradation in the obese zucker rat

1999 ◽  
Vol 10 (4) ◽  
pp. 244-248 ◽  
Author(s):  
Josep M Argilés ◽  
Silvia Busquets ◽  
Belén Alvarez ◽  
Francisco J López-Soriano
Keyword(s):  
Skeletal Muscle ◽  
Protein Degradation ◽  
Muscle Protein ◽  
Zucker Rat ◽  
Skeletal Muscle Protein ◽  
Obese Zucker Rat ◽  
Muscle Protein Degradation

Effect of feeding butoxybutyl alcohol on the growth performance and status of skeletal muscle proteolysis in broiler chickens

2015 ◽  
Vol 153 (5) ◽  
pp. 920-928 ◽  
Author(s):  
T. KAMIZONO ◽  
D. SAPUTRA ◽  
I. MIURA ◽  
M. KIKUSATO ◽  
K. HAYASHI ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Degradation ◽  
Broiler Chickens ◽  
Muscle Protein ◽  
Basal Diet ◽  
Growth Promoter ◽  
Mrna Levels ◽  
Skeletal Muscle Protein ◽  
Final Body Weight ◽  
Muscle Protein Degradation

SUMMARYButoxybutyl alcohol (BBA) is a possible growth promoter contained in the fermentation and distillation by-products of a traditional Japanese spirit, shochu. In the present study, BBA was synthesized and its chemical structure was confirmed by gas chromatography mass spectrometry and nuclear magnetic resonance. Then, two studies were conducted to investigate the effects of feeding the synthesized BBA on the growth and skeletal muscle proteolysis of broiler chickens. Ross male broiler chickens were divided into two groups, control (basal diet: 219 g crude protein/kg and 12·66 MJ metabolizable energy/kg) and BBA diet (30 mg BBA/kg basal diet), with the experimental diets being provided from 15 to 27 days and 0 to 27 days of age, for Studies 1 and 2, respectively. Butoxybutyl alcohol supplementation increased final body weight in both studies, whereas feed intake was unchanged, thereby indicating significantly increased feed efficiency. Furthermore, the synthesized BBA increased the weights of the pectoralis superficialis and profundus muscles, and the leg. The BBA decreased the Nτ-methylhistidine concentration in the excrement and plasma, which are indices of the rate of skeletal muscle protein degradation. It also decreased the mRNA levels of μ-calpain large subunit, atrogin-1/muscle atrophy F-box (MAFbx), ubiquitin and 20S proteasome C2 subunit. These suggest that growth promotion due to the feeding of synthesized BBA is caused by the suppression of skeletal muscle protein degradation, which is related to a decrease in gene expression in the calpain and ubiquitin–proteasome systems.

scholarly journals Specificity of the effects of leucine and its metabolites on protein degradation in skeletal muscle

1984 ◽  
Vol 222 (3) ◽  
pp. 579-586 ◽  
Author(s):  
W E Mitch ◽  
A S Clark
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Protein Degradation ◽  
Muscle Protein ◽  
Adult Rats ◽  
Limb Muscles ◽  
Leucine Catabolism ◽  
Muscle Protein Degradation ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

The effects of leucine, its metabolites, and the 2-oxo acids of valine and isoleucine on protein synthesis and degradation in incubated limb muscles of immature and adult rats were tested. Leucine stimulated protein synthesis but did not reduce proteolysis when leucine transamination was inhibited. 4-Methyl-2-oxopentanoate at concentrations as low as 0.25 mM inhibited protein degradation but did not change protein synthesis. The 2-oxo acids of valine and isoleucine did not change protein synthesis or degradation even at concentrations as high as 5 mM. 3-Methylvalerate, the irreversibly decarboxylated product of 4-methyl-2-oxopentanoate, decreased protein degradation at concentrations greater than or equal to 1 mM. This was not due to inhibition of 4-methyl-2-oxopentanoate catabolism, because 0.5 mM-3-methylvalerate did not suppress proteolysis, even though it inhibited leucine decarboxylation by 30%; higher concentrations of 3-methylvalerate decreased proteolysis progressively without inhibiting leucine decarboxylation further. During incubation with [1-14C]- and [U-14C]-leucine, it was found that products of leucine catabolism formed subsequent to the decarboxylation of 4-methyl-2-oxopentanoate accumulated intracellularly. This pattern was not seen during incubation with radiolabelled valine. Thus, the effect of leucine on muscle proteolysis requires transamination to 4-methyl-2-oxopentanoate. The inhibition of muscle protein degradation by leucine is most sensitive to, but not specific for, its 2-oxo acid, 4-methyl-2-oxopentanoate.

Modulating Influence ofd,l-Propranolol on Triiodothyronine-Induced Skeletal Muscle Protein Degradation*

Endocrinology ◽  
1985 ◽  
Vol 117 (3) ◽  
pp. 869-871 ◽  
Author(s):  
JEFFREY L. MILLER ◽  
FIRHAAD ISMAIL ◽  
J. KRISTINA WALIGORA ◽  
WIELAND GEVERS
Keyword(s):  
Skeletal Muscle ◽  
Protein Degradation ◽  
Muscle Protein ◽  
Skeletal Muscle Protein ◽  
Muscle Protein Degradation
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