Brain - Metabolic Flashcards
DDx hypoglycemia
- Decreased production
PSS
Acute liver failure
Chronic end-stage hepatopathy
Hypoadrenocorticism
GSD - Increased removal
Insulin: overdose, insulinoma, insulin-like substance-producing tumors (melanoma, carcinoma, hepatoma)
Polycythaemia
Toxic (xylitol)
Renal glycosuria
Unknown: sepsis, renal failure, cardiopulmonary arrest, hunting dog, Babesia
DDx hypocobalaminaemia
Exocrine pancreatic insufficiency
Small intestine dysbiosis
Chronic severe ileal disease
Inherited
What is the Imerslund-Gräsbeck syndrome mechanism? How to make the diagnose?
Decreased intracellular cobalamin
Decreased methylmalonic-CoA mutase activity
Accumulation of intracellular methylmalonic acid
Methylmalonic acidaemia & aciduria
Inhibits carbamoyl phosphate synthase I
Hyperammonaemia
Diagnosis:
Decreased B12
Increased methylmalonic acid (urine, serum)
Increased homocysteine (serum)
Kather, 2020
ingestion and absorption of cobalmamin
mainly ingested with food of animal origin (fish, meat, milk product)
intestinal microbiota can produce vit B12 but distally to absorption site
bound to dietary protein -> released in stomach by pepsinogen and gastric acid -> bound to haptocorrin (transcobalamin I) -> separated in duodenum by protease and bound to intrinsic factor -> cubam receptor-mediated endocytosis in ileum -> bound to transcobalamin within bloodstream
1% absorbed via passive diffusion in intestinal mucosa
cobalamin is a cofactor for …
intracellular enzymes methionine synthase and methylmalonyl-CoA mutase
markers that most closely reflect the intracellular availability of cobalamin
serum concentration of methylmalonic acid and homocystein
2 breeds with predisposition to hypocobalaminemia
Giant Schnauzer
Australian Sheperd
Border Collie
Beagle
Chinese Shar-Pei
Komondor
