title: Dietary Manganese Modulates PCB126 Toxicity, Metal Status, and MnSOD in the Rat.
abstract: PCB126 (3,3',4,4',5-pentachlorobiphenyl) is a potent aryl hydrocarbon receptor agonist and induces oxidative stress. Because liver manganese (Mn) levels decrease in response to PCB126, a Mn dietary study was designed to investigate the role of Mn in PCB126 toxicity. Male Sprague Dawley rats received diets containing 0, 10, or 150 ppm added Mn for 3 weeks, followed by a single ip injection of corn oil or PCB126 (5 µmol/kg body weight). After 2 weeks, Mn, Cu, Zn, and Fe levels in the heart, liver, and liver mitochondria, and Mn-containing superoxide dismutase (MnSOD) and metallothionein mRNA, MnSOD protein, and MnSOD activity were determined. Mn levels in liver, heart, and liver mitochondria were strongly decreased by the Mn-deficient diet. Small effects on Fe levels and a stepwise increase in MnSOD activity with dietary Mn were also visible. PCB126 caused profound changes in Cu (up), Zn, Fe, and Mn (down) in liver, but not in heart, and differing effects (Cu, Zn, and Fe up, Mn down) in liver mitochondria. Liver MnSOD and metallothionein mRNA levels and MnSOD protein were increased but MnSOD activity was decreased by PCB126. PCB126-induced liver enlargement was dose-dependently reduced with increasing dietary Mn. These changes in metals homeostasis and MnSOD activity in liver but not heart may be a/the mechanism of PCB126 liver-specific toxicity. Specifically, transport of Fenton metals (Cu, Fe) into and Mn out of the mitochondria, a probable mechanism for lower MnSOD activity, may be a/the cause of PCB126-induced oxidative stress. The role of metallothioneins needs further evaluation. Dietary Mn slightly alleviated PCB126-induced toxicities.
authors.affiliation: *The Interdisciplinary Graduate Program in Human Toxicology and.
authors.forename: Bingxuan
authors.initials: B
authors.lastname: Wang
authors.affiliation: *The Interdisciplinary Graduate Program in Human Toxicology and.
authors.forename: William D
authors.initials: WD
authors.lastname: Klaren
authors.affiliation: State Hygienic Laboratory, The University of Iowa, Iowa City, Iowa;
authors.forename: Brian R
authors.initials: BR
authors.lastname: Wels
authors.affiliation: State Hygienic Laboratory, The University of Iowa, Iowa City, Iowa;
authors.forename: Donald L
authors.initials: DL
authors.lastname: Simmons
authors.affiliation: Department of Pathobiology and Population Medicine, Mississippi State University College of Veterinary Medicine, Statesville, Mississippi;
authors.forename: Alicia K
authors.initials: AK
authors.lastname: Olivier
authors.affiliation: Department of Biostatistics and.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: *The Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, Iowa City, Iowa.
authors.forename: Larry W
authors.initials: LW
authors.lastname: Robertson
authors.affiliation: *The Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, Iowa City, Iowa. gabriele-ludewig@uiowa.edu.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Ludewig
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002254:Carbonates / Q000378:metabolism / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000633:toxicity*; D015870:Gene Expression / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D008297:Male; D008345:Manganese / Q000378:metabolism / Q000494:pharmacology*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D009929:Organ Size / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*
chemical_list: D002254:Carbonates; D004785:Environmental Pollutants; D008345:Manganese; C045327:manganese carbonate; D011078:Polychlorinated Biphenyls; D013482:Superoxide Dismutase; C023035:3,4,5,3',4'-pentachlorobiphenyl
keywords: MnSOD; PCB126; aryl hydrocarbon receptor; diet; manganese; metallothionein