Enhanced intestinal nickel absorption in iron-deficient rats

The absorption of nickel was studied in isolated perfused jejunal and ileal segments of iron-deficient and iron-sufficient rats. The uptake of nickel in tissues of iron-deficient and iron-sufficient rats given a low oral nickel-dose was also examined. The results showed enhanced nickel absorption in vitro and in vivo in iron-deficient rats. In the in vitro perfusions, increased absorption was observed both in jejunum and ileum. The enhancement was very prominent in jejunum and the nickel concentration in the jejunal absorbate of iron-deficient rats even exceeded the nickel concentration in the perfusate. This indicates that nickel is absorbed actively in the jejunum of iron-deficient animals. Twenty-four hr after an oral dose of nickel the uptake of the metal in various tissues was 1.5-2.5 times higher in iron-deficient rats compared to iron-sufficient rats. Our data indicate that nickel is absorbed at least in part by the active transfer system for iron in intestinal mucosal cells.