Vitamin B12 Absorbsion Ve Malabsorbsionu

Year 1977, Volume: 30 Issue: 1, 335 - 352, 31.03.1977

Abdülkadir Dökmeci

https://izlik.org/JA74ZR92SE

Abstract

Proteine bağlı olarak besinlerlerle alınan vitamin B12, mide ve ince barsağın üst kısmında proteinden ayrılır ve GIF ile bira leşir. Oluşan GIF-vitamin B12 kompleksi enzimler, bakteriler ve diğer faktörlerden etkilenmeden ileumun son kısmına ulaşır. Fırçamsı kenarda özel reseptörlere yapışır. Epitel hücresinde GIF'den ayrılan ve daha çok mitokondride toplanan vitamin B12, spesifik bağlayıcılar olan transkobalaminler tarafından portal yol ile depolara taşınır.
Vitamin B12 malabsorbsiyonu en sık GIF yokluğu ve GIF'e karşı antikor varlığı ile karakterli pernisiyöz anemide görülür. Gastrektomi, ileumun distalini tutan ince barsak hastalıkları, kör halka sendromu, kronik pankreatitis, Dyphyllobotrium Latum infestasyonu ve diğer bazı hastalıklarda vitamin B12 ab* sorbsiyonu bozulur.

Keywords

b12 , malabsorbsiyon , gastroenteroloji

Supporting Institution

ankara üniversitesi tıp fakültesi

Absorbtion And Malabsorption Of Vitamin B12

https://izlik.org/JA74ZR92SE

Abstract

Vitamin B12 which is intaken in with diatery protein is released from proteins in the stomach and proximal part of the small intestine binds to GIF. GIF-vitamin B12 complex reaches the terminal ileum without having been affected by enzymes, bacteria and other factors. It atteches to spectific receptors on the brush border. Vitamin B12 which is released from GIF on the ileal mucosal cell is accumulated mainly in the mitochondria and then is storaged by transcobalamins which are specific binders, passing through portal circulation.
Malabsorption of vitamin B12 may occur generally with pernicious anemia characterized with lack of GIF and the existance of antibodies against GIF. Malabsorption of vitamin B12 may also occur with gastrectomy, disease of the terminal ileum, blind loop syndrome, pancreatic dysfunction, dyphyllobotrium latum infestation and some other diseases.

Keywords

b12 , malabsorbtion , gastroenterology

Supporting Institution

ankara university school of medicine

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