title: Copper transport to mammary gland and milk during lactation in rats.
abstract: The delivery of copper to mammary gland and milk and the effects of lactation were examined in rats. Traces of (67)Cu/(64)Cu(II) were injected intraperitoneally or intravenously into virgin rats or lactating rats (2-5 days postpartum), and incorporation into blood, milk, and tissues was monitored. In virgin rats, most of the isotope first entered the liver and kidney. In lactating rats, almost 60% went directly to the mammary gland. Uptake rates and copper contents of the mammary gland were 20-fold higher in lactation. (67)Cu/(64)Cu appeared in milk and milk ceruloplasmin as rapidly as in mammary tissue and when there was no (67)Cu/(64)Cu-ceruloplasmin in the maternal plasma. Plasma (125)I-labeled albumin entered milk much more slowly. Milk ceruloplasmin (10 mg/l) had 25% of the (67)Cu/(64)Cu. Milk copper was 3.3 mg/l. Thus lactation markedly enhances the avidity of the mammary gland for copper, diverting most of it from liver and kidney to that tissue. Also, the primary source of milk ceruloplasmin is the mammary gland and not the maternal plasma.
authors.affiliation: Department of Chemistry and Biochemistry, and Institute for Molecular Biology and Nutrition, California State University, Fullerton, California 92834-6866, USA.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Donley
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Ilagan
authors.forename: Hisun
authors.initials: H
authors.lastname: Rim
authors.forename: Maria C
authors.initials: MC
authors.lastname: Linder
mesh_terms: D000418:Albumins / Q000493:pharmacokinetics; D000818:Animals; D002570:Ceruloplasmin / Q000378:metabolism; D003300:Copper / Q000493:pharmacokinetics*; D003301:Copper Radioisotopes; D005260:Female; D007457:Iodine Radioisotopes; D007774:Lactation / Q000502:physiology*; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008892:Milk / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012726:Sexual Behavior, Animal; D014018:Tissue Distribution
chemical_list: D000418:Albumins; D003301:Copper Radioisotopes; D007457:Iodine Radioisotopes; D003300:Copper; D002570:Ceruloplasmin