Early and long-term changes of equine skeletal muscle in response to endurance training and detraining

2000 ◽  
Vol 441 (2-3) ◽  
pp. 263-274 ◽  
Author(s):  
A.L. Serrano ◽  
E. Quiroz-Rothe ◽  
J.-L.L. Rivero
Keyword(s):  
Skeletal Muscle ◽  
Endurance Training ◽  
Long Term Changes ◽  
Training And Detraining

scholarly journals Adaptation of mitochondrial ATP production in human skeletal muscle to endurance training and detraining

1992 ◽  
Vol 73 (5) ◽  
pp. 2004-2010 ◽  
Author(s):  
R. Wibom ◽  
E. Hultman ◽  
M. Johansson ◽  
K. Matherei ◽  
D. Constantin-Teodosiu ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cytochrome C ◽  
Endurance Training ◽  
Enzyme Activities ◽  
Citrate Synthase ◽  
Mitochondrial Fraction ◽  
Mitochondrial Enzyme ◽  
Atp Production ◽  
Before And After ◽  
Training And Detraining

The adaptation of mitochondrial ATP production rate (MAPR) to training and detraining was evaluated in nine healthy men. Muscle samples (approximately 60 mg) were obtained before and after 6 wk of endurance training and after 3 wk of detraining. MAPR was measured in isolated mitochondria by a bioluminometric method. In addition, the activities of mitochondrial and glycolytic enzymes were determined in skeletal muscle. In response to training, MAPR increased by 70%, with a substrate combination of pyruvate + palmitoyl-L-carnitine + alpha-ketoglutarate + malate, by 50% with only pyruvate + malate, and by 92% with palmitoyl-L-carnitine + malate. With detraining MAPR decreased by 12–28% from the posttraining rate (although not significantly for all substrates). No differences were found when MAPR was related to the protein content in the mitochondrial fraction. The largest increase in mitochondrial enzyme activities induced by training was observed for cytochrome-c oxidase (78%), whereas succinate cytochrome c reductase showed only an 18% increase. The activity of citrate synthase increased by 40% and of glutamate dehydrogenase by 45%. Corresponding changes in maximal O2 uptake were a 9.6% increase by training and a 6.0% reversion after detraining. In conclusion, both MAPR and mitochondrial enzyme activities are shown to increase with endurance training and to decrease with detraining.

scholarly journals Effects of a Ketogenic Diet Containing Medium-Chain Triglycerides and Endurance Training on Metabolic Enzyme Adaptations in Rat Skeletal Muscle

Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1269 ◽  
Author(s):  
Ayumi Fukazawa ◽  
Atsuko Koike ◽  
Takuya Karasawa ◽  
Momoko Tsutsui ◽  
Saki Kondo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Content ◽  
Endurance Training ◽  
Ketogenic Diet ◽  
Negative Regulator ◽  
Medium Chain Triglycerides ◽  
Rat Skeletal Muscle ◽  
Medium Chain ◽  
Coa Transferase

Long-term intake of a ketogenic diet enhances utilization of ketone bodies, a particularly energy-efficient substrate, during exercise. However, physiological adaptation to an extremely low-carbohydrate diet has been shown to upregulate pyruvate dehydrogenase kinase 4 (PDK4, a negative regulator of glycolytic flux) content in skeletal muscle, resulting in impaired high-intensity exercise capacity. This study aimed to examine the effects of a long-term ketogenic diet containing medium-chain triglycerides (MCTs) on endurance training-induced adaptations in ketolytic and glycolytic enzymes of rat skeletal muscle. Male Sprague-Dawley rats were placed on either a standard diet (CON), a long-chain triglyceride-containing ketogenic diet (LKD), or an MCT-containing ketogenic diet (MKD). Half the rats in each group performed a 2-h swimming exercise, 5 days a week, for 8 weeks. Endurance training significantly increased 3-oxoacid CoA transferase (OXCT, a ketolytic enzyme) protein content in epitrochlearis muscle tissue, and MKD intake additively enhanced endurance training–induced increases in OXCT protein content. LKD consumption substantially increased muscle PDK4 protein level. However, such PDK4 increases were not observed in the MKD-fed rats. In conclusion, long-term intake of ketogenic diets containing MCTs may additively enhance endurance training–induced increases in ketolytic capacity in skeletal muscle without exerting inhibitory effects on carbohydrate metabolism.

Canine diaphragm muscle after 1 yr of continuous electrical stimulation: its potential as a myocardial substitute

1987 ◽  
Vol 62 (3) ◽  
pp. 1264-1270 ◽  
Author(s):  
M. A. Acker ◽  
J. D. Mannion ◽  
W. E. Brown ◽  
S. Salmons ◽  
J. Henriksson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fiber Type ◽  
Diaphragm Muscle ◽  
Type I ◽  
Normal Heart ◽  
Chronic Stimulation ◽  
Normal Heart Rate ◽  
Type Composition ◽  
Long Term Changes

Skeletal muscle has been rendered fatigue resistant by chronic stimulation and therefore has potential as an active substitute for damaged myocardium. It is therefore important to know whether stimulation produces any deleterious effects in the long term. Hemidiaphragm muscles of four dogs were examined after chronic stimulation for 1 yr at either 2 or 4 Hz. The stimulated hemidiaphragms appeared normal on gross inspection and were still contracting vigorously. By histochemical and immunohistochemical criteria, they had acquired a uniformly type I character, in contrast to the mixed fiber type composition of the unstimulated hemidiaphragms. This transformation was also reflected in their complement of myosin isozymes. There was some enzymatic evidence of an associated shift towards aerobic pathways of energy generation. Histological examination revealed no evidence of degenerative changes. Trends, observed in the shorter term (6–8 wk), toward a decrease in fiber area and an increase in connective tissue showed no further progression at 1 yr. Thus hemidiaphragm muscle stimulated at frequencies at or above the normal heart rate does not appear to undergo adverse long-term changes that would constrain its use in a myocardial assist role.

Effect of 12-month resistance and endurance training on quality, quantity, and function of skeletal muscle in older adults requiring long-term care

2017 ◽  
Vol 98 ◽  
pp. 230-237 ◽  
Author(s):  
Akito Yoshiko ◽  
Takashi Kaji ◽  
Hiroki Sugiyama ◽  
Teruhiko Koike ◽  
Yoshiharu Oshida ◽  
...  
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Endurance Training ◽  
Long Term Care ◽  
Term Care ◽  
And Function
Sign in / Sign up

Export Citation Format

Share Document