It is believed that the biochemical functions of copper are provided by approximately one dozen mammalian cuproenzymes, copper-binding proteins, that catalyze important biochemical reactions (Failla et al., 2001).Optimal copper homeostasis also depends on expression of a number of copper chaperone proteins and copper import and efflux transporters (Prohaska and Gybina, 2004).Rodent Cp activity rose during lactation whereas PAM activity fell.Reduction in Cp activity was more severe than reduction in PAM activity in Cu− offspring and dams.A preliminary study in humans with a variant of Menkes' disease, an inherited disorder with symptoms of copper deficiency, suggested that plasma PAM might be useful to assess copper status in humans (Prohaska et al., 1997).However, PAM has not been evaluated during pregnancy and lactation, nor in experimental mammals besides the albino rat.Even when dietary copper is limiting, liver is fully capable of synthesizing and secreting Cp protein into the plasma after it is fully glycosylated (Holtzman and Gaumnitz, 1970; Gitlin et al., 1992).
Both cuproenzymes changed during neonatal development and when dietary copper was limiting.
One such factor is the essential transition metal, copper.
North American recommendations set by the Food and Nutrition Board, Institute of Medicine, National Academy of Sciences suggest that adults consume 900 µg of copper a day to provide an adequate supply to support physiological functions of this metal.
In an attempt to identify a sensitive and improved marker of mammalian copper status during neonatal development experiments compared two plasma cuproenzymes, peptidylglycine α-amidating monooxygenase (PAM ), an enzyme involved in peptide posttranslational activation, to ceruloplasmin (Cp), a ferroxidase involved in iron mobilization.
Dietary Cu deficiency (Cu−) was studied in dams and offspring at postnatal age 3 (P3), P12, and P28.