A new role for an old hormone: is gastrin a cofactor for dietary metal ion uptake?
It is proposed that gastrin promotes the uptake of divalent and trivalent metal ions from the gastrointestinal lumen by catalyzing the binding of metal ions to luminal albumin and transferrin respectively. The following observations are consistent with this hypothesis: 1. Gastrin binds both divalent and trivalent metal ions. 2. Gastrin binds to both albumin and apotransferrin. 3. Binding of gastrin to albumin is enhanced by divalent metal ions. 4. Gastrin, albumin and transferrin are all present in gastric juice. 5. Surgical removal of the gastric mucosa results in iron deficiency.
Baldwin
G S
GS
Melbourne Tumour Biology Branch, Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Victoria, Australia.
D000595:Amino Acid Sequence; D000818:Animals; D002413:Cations, Divalent; D004032:Diet; D004068:Digestive System Physiological Phenomena; D005753:Gastric Mucosa / Q000502:physiology; D005755:Gastrins / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007413:Intestinal Mucosa / Q000502:physiology; D008670:Metals / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism; D014168:Transferrin
D002413:Cations, Divalent; D005755:Gastrins; D008670:Metals; D012709:Serum Albumin; D014168:Transferrin