title: Milk ceruloplasmin is a valuable source of nutrient copper ions for mammalian newborns.
abstract: This research focuses on the role of milk ceruloplasmin (Cp), the main extracellular copper-containing protein of vertebrates, as a source of copper for newborns. In the first part of the study, Cp concentration and Cp-associated copper were measured in human skimmed milk at the 1st and the 5th days postpartum. It was shown that most of the copper was associated with Cp and that the decrease in copper concentration during lactation was related to the drop of Cp levels. The following in vivo experiments demonstrated that milk [(125)I]Cp per os administered to 6-day-old rats (embryonic-type copper metabolism) was transported into their bloodstream. The electrophoretic mobility and relative molecular weight of [(125)I]Cp transferred through the cellular barrier remained unaltered. However, 22-day-old rats (adult-type copper metabolism) digested the administered milk [(125)I]Cp completely. In the final part of the study, newborn rats were fed with baby formula for 8d. It was found that these rats switched their copper metabolism from embryonic type to adult type earlier than their littermates fed by dams. Activation of Cp gene expression in the liver, increased Cp and copper concentrations in the blood, and reduced copper content of the liver were observed in the rats fed with baby formula. In the brain, no copper concentration change was observed, but Cp and copper concentrations were dramatically increased in the cerebrospinal fluid. The role of milk Cp as a source of copper adapted to embryonic-type copper metabolism is discussed.
authors: Department of Molecular Genetics, Research Institute for Experimental Medicine, Pavlov Str, 12, 197376 St Petersburg, Russian Federation.
authors: Natalia
authors: N
authors: Platonova
authors: Natalie
authors: N
authors: Guolikhandanova
authors: Nadezhda
authors: N
authors: Tsymbalenko
authors: Evelyn
authors: E
authors: Zhiguleva
authors: Tatiana
authors: T
authors: Zhivulko
authors: Andrey
authors: A
authors: Vasin
authors: Inna
authors: I
authors: Evsukova
authors: Ludmila
authors: L
authors: Puchkova
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002570:Ceruloplasmin / Q000737:chemistry* / Q000378:metabolism; D003300:Copper / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D006801:Humans; D041943:Infant Formula / Q000737:chemistry; D008892:Milk / Q000737:chemistry*; D008895:Milk, Human / Q000737:chemistry*
chemical_list: D003300:Copper; D002570:Ceruloplasmin