1. Arsenic Poisoning
    • aresenite most toxic form
    • Acts on enzymes containing
    • lipoic acid (ex: PDH, glyceraldehyde 3 phophate dehydrogenase)
    • Reoxidizes the reduced
    • disulfide bond --> increases its stability so pyruvate and lactate
    • builds up
    • Causes a decrease in E.
    • production ---> acidosis
  2. Thiamine Deficiency
    • Deficiency in thiamine
    • (vitamin B1) results in PDH complex E1 not being able to decarboxylate
    • pyruvate because the enzyme will present as an apoenzyme with no thiamine
    • pyrophosphate cofactor bound to it

    • Mild deficiency: GI
    • complaints, "pins and needles"/burning feet
    • Severe deficiency: Beri-Bery
    • or Wernicke-kOrsakoff Syndrome
  3. Beri-Beri
  4. Asia- eating polished rice
    • with husk removed (source of thyiamine)
    • Wet and dry type- depending
    • if edema is present or not
    • Nueromuscular cardiovascular
    • disorders, delirium, memory loss, muscle weakining, increased venous
    • return to heart, peripheral vasodilation, opthalomogplegia
    • Death by high output cardiac
    • failure
  5. Wernicke-Korsakoff Syndrome
    • Chronic alcohol abuse &
    • poor nutrition
    • Wernicke's encephalopathy
    • (acute phase): delerium, mental derangement, ataxia, opthalmoplegia
    • Korsakoff psychosis (chronic
    • phase)- anterograde amnesia, distinct pattern of brain damage (focal
    • adhesions) …IRREVERSIBLE
    • Diagnosis- urinary thiamine
    • excretion, transketolase activity in RBC, lactate/pyruvate levels
    • post-oral glucose pill
    • Treatment- thiamine
    • injections intramuscularly (before chronic phase)
  6. PDH Deficiency
    • Defect of E1
    • Inability to convert pyruvate
    • to acetyl coA
    • X linked dominant (but both M
    • and F)
    • Increase blood levels of:
    • pyruvate, lactate, alanine, alpha keto glutarate
    • Causes congenital lactic
    • acidosis
    • Symptoms: mental retardation,
    • microcephaly, otpical atrophy, motor dysfunction, spinocerebllar ataxia
    • Treatment: low car diet
Card Set
BCHM term 1