Iron deficiency anaemia is the most common nutritional disorder worldwide. Anaemia is especially serious during pregnancy, where Fe deficiency has deleterious consequences for the mother and her developing fetus. The mother has therefore evolved various adaptations to increase dietary Fe absorption during pregnancy. In this study we investigated these adaptations at the primary site of Fe absorption, the duodenal mucosa, in dams and neonates in response to Fe deficiency.
Weanling Female Hooded Lister rats were placed on a control diet for 2 weeks, then on either a normal (50 mg kg-1) or decreased (7.5 mg kg-1) Fe content diet for 4 weeks prior to mating. The rats were maintained on the same diet throughout pregnancy. Duodenal biopsies, taken after stunning and cervical dislocation, were used to determine in vitro 59Fe uptake (µg Fe uptake/g wet weight) immediately following birth in dams and pups.
An increase in Fe uptake was observed in the pups (n = 8, control 36 ± 6, deficient 114 ± 19 P = 0.002), and the dams (n = 8, cntl 7.0 ± 0.88, deficient 39.5 ± 8.4 P = 0.005) placed on an Fe deficient diet. These changes correlated to liver Fe levels (µg/g dry weight), which were reduced in the Fe deficient pups (n = 8, cntl 2640 ± 312, deficient 1713 ± 168 P = 0.029). Duodenal mucosa was also collected for mRNA analysis. Expression of Fe uptake, Divalent Metal Transporter 1 (DMT1), and Fe efflux, Ireg1, genes was determined by quantitative real-time PCR. Expression levels were normalised to that of actin for individual samples. In the Fe deficient pups an increase in DMT1 (cntl 2.75 ± 1.11 n = 9, deficient 13.1 ± 2.07 n = 5 P = 0.0004) and Ireg1 (cntl 15.3 ± 6.1 n = 9, deficient 44.5 ± 7.93 n = 5 P = 0.017) was observed. Suprisingly these changes were not reflected in the Fe deficient dams, DMT1 (cntl 1360 ± 460 n = 6, deficient 1740 ± 267 n = 7 P = 0.503 and Ireg1 (cntl 74.0 ± 4.21 n = 9, deficient 60.4 ± 8.26 n = 5 P = 0.172). All values given as mean ± S.E.M., Student’s unpaired t test was used to determined significance between two sets of data. P < 0.05 were considered significant.Fe deficiency during pregnancy caused a decrease in liver iron levels, and an increase in duodenal Fe uptake in newborn pups, this was a result of increased DMT1 and Ireg1 expression. Fe deficient dams also showed elevated duodenal Fe uptake, although to a lesser extent then that of the pups, also this increase was not a consequence of upregulated DMT1 and Ireg1 expression.
This work was funded by the European Union