title: Elevation of brain manganese in calcium-deficient rats.
abstract: Rats, 3 weeks of age, consumed diets low or normal in calcium (Ca) with or without supplemental manganese (Mn) as Mn (II) acetate in drinking water. After 6 weeks, the animals were killed and [Mn] was determined in 8 brain regions, spinal cord, liver, serum, kidney, femur, and skeletal muscle. Serum [Mn] increased 1.5-, 4-, and 40-fold respectively, in normal Ca-supplemented Mn rats, low Ca rats, and low Ca-supplemented Mn rats. Elevation of tissue [Mn] occurred in all experimental groups with the greatest changes in the low Ca-extra Mn group: 6 - 12 fold in brain and spinal cord, and 2.5 - 140 fold in muscle, liver, kidney, and femur. Ratios of serum [Mn]/tissue [Mn] decreased as serum [Mn] increased suggesting saturable distribution. The findings suggest that Ca deficiency may cause Mn neurotoxicity by increasing dietary Mn absorption and brain [Mn].
authors.affiliation: Laboratory of Neurosciences, National Institute of Aging, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: V A
authors.initials: VA
authors.lastname: Murphy
authors.forename: J M
authors.initials: JM
authors.lastname: Rosenberg
authors.forename: Q R
authors.initials: QR
authors.lastname: Smith
authors.forename: S I
authors.initials: SI
authors.lastname: Rapoport
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000172:deficiency*; D008297:Male; D008345:Manganese / Q000378:metabolism*; D020149:Manganese Poisoning; D051381:Rats; D011916:Rats, Inbred F344; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism; D014018:Tissue Distribution / Q000187:drug effects
chemical_list: D008345:Manganese; D002118:Calcium