Title: Iron absorption - unknown properties of gastric mucins
- Wojciech Janusz Baranowski
- Contemporary Pediatrics, Gastroenterology, Hepatology and Child Feeding
- Start page:
- Final page:
- iron, absorption, mucins, mucus, valence tautomerism
Introduction: It is accepted, that Fe (III) is being absorbed by the organism after reducing for Fe (II). Objectives: Speciation of iron in compounds with gastric mucins.
Materials and methods: "Mucin type II crude from porcine stomach" (Sigma-Aldrich), HCI, KOH, FeCI2-6H2O and FeCI3-6H2O (POCH, Gliwice), deionized water of conductance 70 uS, chromatographic paper Whatman no. 4, Blades TLC 60 F254 type E (Merck). Ascending pa-per and thin-layer chromatography.
Results: Fe3+ and Fe2+ react with gastric mucins in solutions of pH value ca. 1 giving compounds that are stable in pH rangę pH 1-10. Chro-matograms of mucin-Fe3+ and mucin-Fe2+ can be developed with both 2.2'-dipyridile and potassium thiocyanate. It means that some of Fe (II) was oxidized to Fe (III) and some of Fe (III) was reduced to Fe (II).
Conclusions: Gastric mucins can react and bond with Fe3+ and Fe2+ - both compounds can be absorbed. Iron-mucin compounds are sho-wing valence tautomerism that is relying on the ion of the iron being oxidized/reduced and simultaneous the part of mucin being redu-ced/oxidized (intramolecular electron transfer). Occurring valence tautomerism is enabling the organism to control the quantity of the absorbed iron through the modification of the microem/ironment conditions in digestive tract (e.g. pH values of the intestinal content). Smali expenditure of celi energy to change the oxidation state of the iron can be explained with phenomenon valence tautomerism.