All::Gastroenterology::Physiology::Vitamin B1 (thiamine)
Intro
What type of vitamin is vitamin B1?
Water-soluble.
What is a derivative of vitamin B1?
Thiamine pyrophosphate (TPP).
What enzymatic reactions does TPP serve as a coenzyme for?
Pyruvate dehydrogenase complex, pyruvate decarboxylase in ethanol fermentation, alpha-ketoglutarate dehydrogenase complex, branched-chain amino acid dehydrogenase complex, 2-hydroxyphytanoyl-CoA lyase, transketolase.
Why is thiamine important?
It's important in the catabolism of sugars and amino acids.
What are the clinical consequences of thiamine deficiency?
Wernicke-Korsakoff syndrome (seen first in highly aerobic tissues such as the brain), wet beriberi (seen first in the heart).
What are the causes of thiamine deficiency?
Alcohol excess, malnutrition.
What are the conditions associated with thiamine deficiency?
Wernicke's encephalopathy (nystagmus, ophthalmoplegia, ataxia), Korsakoff's syndrome (amnesia, confabulation), dry beriberi (peripheral neuropathy), wet beriberi (dilated cardiomyopathy).