Muscles thiamin diphosphate

Two percent to 3% of the thiamin in nervous tissue is present as the triphosphate, which also occurs in significant amounts in skeletal muscle, especially in fast-twitch muscle fibers. In the nervous system, the triphosphate is found exclusively in the membrane fraction muscle thiamin triphosphate is mainly cytosoUc. There are two pathways for formation of thiamin triphosphate from the diphosphate ... 

Thiamin-Responsive Pyruvate Dehydrogenase Deficiency Genetic deficiency of pyruvate dehydrogenase Ela (which is on the X chromosome) leads to potentially fatal lactic acidosis, with psychomotor retardation, central nervous system damage, atrophy of muscle fibers and ataxia, and developmental delay. At least some cases respond to the administration of high doses (20 to 3,000 mg per day) of thiamin. In those cases where the enzyme has been studied, there is a considerable increase in the of the enzyme for thiamin diphosphate. Female carriers of this X-linked disease are affected to a variable extent, depending on the X-chromosome inactivation pattern in different tissues (Robinson et al., 1996). 

Thiamin triphosphate is formed in brain and skeletal muscle by phosphorylation of thiamin diphosphate (Section 6.2), and its concentration is very precisely controlled, because there is also an active thiamin triphosphatase (Lakaye et al., 2002). In nervous tissue thiamin triphosphate is localized... 

Vitamin Bi, also called thiamine, is required for all tissues and high concentrations are found in skeletal muscle, heart, liver, kidneys and brain. Thiamine diphosphate (TDP) is the active form and it serves as a cofactor for several enzymes involved in carbohydrate catabolism. These enzymes are also important in the biosynthesis of many cellular constituents, including neurotransmitters, and for the production of reducing equivalents used in oxidant stress defenses (Ba 2008). Thiamine is considered an anti-stress vitamin because it strengthens the immune system and improves the body s ability to withstand stress conditions (Haas 1988). 

Thiamin or Bj has been recognized historically as the main cause of beriberi. Thiamin exists in free and bound forms (thiamin diphosphate and the protein-phosphate-thiamin complex). The bound forms are split in the gastrointestinal tract. The absorbed thiamin acts as a coenzyme in energy metabolism, mainly in the conversion of glncose to fats. In addition, it has high implications in the functioning of peripheral nerves (nerve impulses), brain, and muscles. Thiamin deficiency causes... 

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