Ferritin production in the rat small intestine.

Abstract

Summary.Administration of iron to rats increases the amount of [14C]amino acid incorporation into ferritin in the rat intestine. Using a specific anti‐rat ferritin antiserum, several variables affecting de novo synthesis of ferritin in the rat intestine were studied. Synthesis was dose dependent in the range of 1–100 μmoles of oral iron with larger doses producing no greater effect. However, significant ferritin synthesis was evoked by a 150 μmole dose of oral iron in animals pretreated with similar doses of oral iron 3 and 6 hr before the test dose. Cobalt, a cation absorbed by the intestine in a fashion similar to iron, did not stimulate ferritin synthesis. Oral and parenteral iron administration produced different effects on various small intestinal segments. Oral iron induced synthesis chiefly in the proximal small intestine while intravenous iron produced it dominantly in the terminal ileum. These latter findings are consistent with the concept that ferritin functions chiefly as a barrier to excess iron absorption and as an important mechanism for iron excretion.