EFFECTS OF AGE AND MINERAL INTAKE ON THE REGULATION OF IRON
ABSORPTION IN INFANTS
Iron deficiency anemia during infancy is associated with delayed psychomotor and cognitive development; thus there is global interest in improving infant iron status through iron supplementation programs early in life.
In adults, iron homeostasis primarily is controlled through regulatory changes in iron absorption; however, there is little understanding of mechanisms that regulate iron absorption in infants.
As iron stores become depleted from rapid hemoglobin expansion, ontogenic transition to regulated iron absorption must occur.
To elucidate age-dependent mechanisms regulating intestinal iron absorption and homeostasis in human infants, studies in suckling rat pups indicated that increased divalent metal transporter 1 (DMT1), ferroportin 1 (FPN1), and hephaestin expression and changes in localization within the enterocyte may direct the ontogenic regulation of iron homeostasis mechanisms.
Unlike observations in adults, iron absorption, DMT1, and FPN1 expression were not affected by iron intake during mid-infancy, similar to observations in human infants.
Interestingly, at this age supplemental iron was retained in the small intestine, but only in pups that were not previously iron deficient.
Although intestinal retention may possibly help limit excess iron absorption, decreased linear growth, head circumference, and weight gain has been observed in iron-supplemented, nonanemic human infants, suggesting that global iron supplementation programs should be approached with caution.
- 小高Lv 71 decade agoFavorite Answer
因為鐵商店從迅速的血色素擴充變成耗損， ontogenic 轉變到管理鐵吸收一定要發生。
闡明年齡－依賴的機制在人類的嬰兒中管理腸的鐵吸收和體內平衡，研究在哺乳老鼠學生方面指出二價的金屬製的輸送人 1(DMT1) 、 ferroportin 1(FPN1) 和 hephaestin 表達增加和 enterocyte 裡面的本土化方面的改變可能指示鐵體內平衡機制的 ontogenic 條例。
不像成人、鐵吸收、 DMT1 和 FPN1 表達的觀察不是被鐵攝取影響的在之中期間－幼年，類似人類的嬰兒觀察。