Reduction of iron/zinc interactions using metal bound to the caseinophosphopeptide 1-25 of beta-casein

摘要

The isolated, perfused rat duodenal loop system was used to assess the influence of binding Fe to soluble 1-25 caseinophosphopeptide (beta-CN (1-25)), produced by the hydrolysis of beta-casein, against the inhibition of its absorption by Zn. Fe (100鎊250LM) was perfused as Fe gluconate (FeGluc) or bound to the beta-CN (1-25) (Fe-CN), alone (controls) or in the presence of Zn as ZnSO4 or as (Zn-CN) at Fe:Zn ratios ranging from 2:1 to 1:5. ZnSO4 significantly reduced disappearance from the lumen (Q1) andnet Fe absorption at Fe:Zn ratios from 1:1.5 to 1:5 (P<0.001). Fe mucosal retention (Q2) did not change significantly. When Zn was provided as Zn-CN, Q1, Q2 and Fe absorption did not significantly differ from control group for FeGluc. ZnSO4 and Zn-CN did not reduce significantly Q1, Q2 or Fe absorption for Fe-CN whatever ratios considered. It is concluded that binding Fe to beta-CN (1-25) prevented Zn from inhibiting its absorption and this could have therapeutic applications in dietary supplementationof trace-elements.