Iron deficiency in the pregnant rat has differential effects on maternal and fetal copper levels

Iron deficiency during pregnancy causes problems both for the mother and fetus. Iron deficiency is known to have secondary effects on copper metabolism. In this study, we use a rat model to examine the effect of iron deficiency on copper levels in maternal and fetal tissue. We assess whether the effects of iron deficiency on copper metabolism are due to alterations in mRNA levels of proteins of copper transport. Rowett Hooded Lister rats were fed diets with four different iron contents before and during pregnancy. Maternal and fetal samples were collected on day 21 of gestation. Copper and iron levels of liver and placenta were analyzed, mRNA levels of genes involved in copper transport were studied, and copper oxidase activity measured. Reduced dietary iron was found to increase maternal liver copper, inversely correlating with iron levels. Correspondingly, copper and ceruloplasmin increased in maternal serum. The placenta showed the greatest increase in copper levels. As the iron content of the maternal diet decreased so did the iron and copper levels in the fetal liver. In all tissues examined, mRNA expression for CTR1, ATOX1, ATP7A, and ATP7B was unchanged by iron deficiency. However, copper oxidase activity in maternal serum and placenta was increased. Our study in a rat model demonstrates that iron deficiency during pregnancy has a differential effect on copper metabolism in the mother and fetus. It is clear from this study that the changes in copper levels that accompany iron deficiency are not mediated by changes in transcription of the genes involved in copper transport.