Slow twitch oxidative

Tissue-Specific Expression. In adult rodents, PPAR.a is expressed in liver, kidney, intestine, heart, skeletal muscle, retina, adrenal gland, and pancreas. In adult human, PPARa is expressed in the liver, heart, kidney, large intestine, skeletal muscle (mostly slow-twitch oxidative type I fibers), and in cells of atherosclerotic lesions (endothelial cells, smooth muscle cells, and monocytes/macrophages). Therefore, regardless of... 

Histopathological examination shows the typical corelike lesions in a high proportion of muscle fibers in older patients this may amount to 100%. Most typically the cores are large and centrally-placed, but multiple cores may occur in the same fiber cross section. Most older patients show a striking predominance of type 1 (slow twitch oxidative) fibers and virtually all fibers with cores are type 1. Sometimes younger family members have more normal proportions of type 1 and type 2 fibers but, again, the cores are confined to the type 1 fibers. It is well established that muscle fiber types can interconvert due to altered physiological demands, and it is likely that fibers with cores convert to a basically slow twitch-oxidative metabolism to compensate for the fact that up to 50% of their cross sectional area may be devoid of mitochondria. 

Distinguish among the three types of muscle fibers slow-twitch oxidative, fast-twitch oxidative, and fast-twitch glycolytic... 

Feature Slow-twitch oxidative Fast-twitch oxidative Fast-twitch glycolytic... 

Finally, slow-twitch muscle fibers have a small diameter. This facilitates the diffusion of oxygen through the fiber to the mitochondria where it is utilized. Taken together, each of these characteristics enhances the ability of these fibers to utilize oxygen. Therefore, in slow-twitch oxidative muscle... 

Ila (fast-twitch oxidative) and type I (slow-twitch oxidative) muscle fibers have greater oxidative capacity and are less dependent on the cycle than type Ilb (fast-twitch glycolytic) fibers. Thus, gradual exercise programs that lead to production of a greater proportion of type Ila and type I fibers might improve exercise tolerance in AMP deaminase deficiency. 

Exercise limitation and functional disability in COPD have a complex, multifactorial basis. Ventilatory limitation is caused by increased airways resistance, static and dynamic hyperinflation, increased elastic load to breathing, gas exchange disturbances, and mechanical disadvantage and/or weakness of the respiratory muscles (4-6). Car-diocirculatory disturbances (7,8), nutritional factors (9), and psychological factors, such as anxiety and fear, also contribute commonly to exercise intolerance. Skeletal muscle dysfunction is characterized by reductions in muscle mass (10,11), atrophy of type I (slow twitch, oxidative, endurance) (12,13) and type Ila (fast twitch) muscle fibers (14), altered myosin heavy chain expression (15), as well as reductions in fiber capillarization (16) and oxidative enzyme capacity (17,18). Such a dysfunction is another key factor that contributes... 

CK activity, containing large amounts of MM-CK, than slow-twitch oxidative fibers, but the latter have a higher pereentage of Mi-CK. Recent studies suggest that dietary and muscle availabihty of ereatine may influence CK aetivity in various healthy and diseased populations. - ... 

Skeletal muscle contains three types of fiber fast-twitch oxidative glycolytic (type 2A), fast-twitch glycolytic (type 2B), and slow-rwitch oxidative fibers (type 1). The proportion of each fiber type varies in different muscles. Different fiber types contain different isoforms of myosin, although there is no evidence that their mitochondria differ qualitatively. It has been reported that there are differences between subsarcolemmal mitochondria and those deeper in the same fiber but this has been questioned (see Sherratt et al., 1988 for references). 

Muscle Fast twitch Slow twitch Rapid movement Sustained movement Glycolysis Aerobic pathways, eg, p-oxidation and citric acid cycle Glucose Ketone bodies, triacylglycerol in VLDL and chylomicrons, free fatty acids Lactate Lipoprotein lipase. Respiratory chain well developed. 

Different types of fibers have been detected in skeletal muscle. One classification subdivides them into type I (slow twitch), type IIA (fast twitch-oxidative), and type IIB (fast twitch-glycolytic). For the sake of simphcity, we shall consider only two types type I (slow twitch, ox-... 

Fast-twitch muscle fibers have a high capacity for anaerobic glycolysis but are quick to fatigue. They are involved primarily in short-term, high-intensity exercise. Slow-twitch muscle fibers in arm and leg muscles are well vascularized and primarily oxidative. They are used during prolonged, low-to-moderate intensity exercise and resist fatigue. Slow-twitch fibers and the number of their mitochondria increase dramatically in trained endurance athletes. 

Skeletal muscle cells can be subdivided into type I and type IIfibers. Type I fibers are slow-twitch fibers that use primarily oxidative metabolism for energy, whereas the type 11 fibers (fast-twitch) use glycolysis as their primary energy-generating pathway. 

Muscle fibers can be classified as either fast-twitch or slow-twitch. The slow-twitch fibers, or type 1 fibers (also called slow-oxidative), contain large amounts of mitochondria and myoglobin (giving them a red color), utilize respiration and oxidative phosphorylation for energy, and are relatively resistant to fatigue. Compared with fast-twitch fibers, their glycogen content is low. The slow-twitch fibers develop force slowly but maintain contractions longer than fast-twitch muscle. 

Slow-twitch (slow speed of contraction) Slow-oxidative (low glycogen content)... 

Fast twitch, oxidative, glycolytic (FOG) Slow tonic, oxidative (SO)... 

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