Search results
Results from the WOW.Com Content Network
Thiamine deficiency is a medical condition of low levels of thiamine (vitamin B 1). [1] A severe and chronic form is known as beriberi. [1] [7] The name beriberi was possibly borrowed in the 18th century from the Sinhalese phrase බැරි බැරි (bæri bæri, “I cannot, I cannot”), owing to the weakness caused by the condition.
Thiamine pyrophosphate is a cofactor that is present in all living systems, in which it catalyzes several biochemical reactions. Thiamine pyrophosphate is synthesized in the cytosol and is required in the cytosol for the activity of transketolase and in the mitochondria for the activity of pyruvate-, oxoglutarate- and branched chain keto acid ...
The enzymes that are dependent on thiamine pyrophosphate are associated with the citric acid cycle (also known as the Krebs cycle), and catalyze the oxidation of pyruvate, α-ketoglutarate and branched chain amino acids. Thus, anything that encourages glucose metabolism will exacerbate an existing clinical or sub-clinical thiamine deficiency. [15]
Pyruvate dehydrogenase is an enzyme that catalyzes the reaction of pyruvate and a lipoamide to give the acetylated dihydrolipoamide and carbon dioxide. The conversion requires the coenzyme thiamine pyrophosphate. Pyruvate dehydrogenase is usually encountered as a component, referred to as E1, of the pyruvate dehydrogenase complex (PDC). PDC ...
Thiamine (vitamin B 1) may be given if pyruvate dehydrogenase deficiency is known or suspected. The symptoms of lactic acidosis are treated by supplementing the diet with sodium bicarbonate (baking soda) or sodium citrate, but these substances do not treat the cause of Leigh syndrome.
Pyruvate decarboxylation requires a few cofactors in addition to the enzymes that make up the complex. The first is thiamine pyrophosphate (TPP), which is used by pyruvate dehydrogenase to oxidize pyruvate and to form a hydroxyethyl-TPP intermediate. This intermediate is taken up by dihydrolipoyl transacetylase and reacted with a second ...
Korsakoff syndrome (KS) [1] is a disorder of the central nervous system characterized by amnesia, deficits in explicit memory, and confabulation.This neurological disorder is caused by a deficiency of thiamine (vitamin B 1) in the brain, and it is typically associated with and exacerbated by the prolonged, excessive ingestion of alcohol. [2]
Pseudohypoxia refers to a condition that mimics hypoxia, by having sufficient oxygen yet impaired mitochondrial respiration due to a deficiency of necessary co-enzymes, such as NAD + and TPP. [ 1 ] [ 2 ] [ 3 ] The increased cytosolic ratio of free NADH/NAD + in cells (more NADH than NAD + ) can be caused by diabetic hyperglycemia and by ...