Chromium Selectively Accumulates in the Rat Hippocampus after 90 Days of Exposure to Cr(VI) in Drinking Water and Induces Age- and Sex-Dependent Metal Dyshomeostasis
Samuel T. Vielee,
William J. Buchanan,
Spencer H. Roof,
Rehan Kahloon,
Elizabeth Evans,
Jessica Isibor,
Maitri Patel,
Idoia Meaza,
Haiyan Lu,
Aggie R. Williams,
J. Calvin Kouokam,
Sandra S. Wise,
Luping Guo,
Rachel M. Wise,
Jamie L. Wise,
Lu Cai,
Jun Cai,
John P. Wise
Affiliations
Samuel T. Vielee
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
William J. Buchanan
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
Spencer H. Roof
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
Rehan Kahloon
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
Elizabeth Evans
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
Jessica Isibor
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
Maitri Patel
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
Idoia Meaza
Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA
Haiyan Lu
Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA
Aggie R. Williams
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
J. Calvin Kouokam
Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA
Sandra S. Wise
Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA
Luping Guo
Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA
Rachel M. Wise
Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Albuquerque, NM 87131, USA
Jamie L. Wise
Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA
Lu Cai
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
Jun Cai
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
John P. Wise
Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40292, USA
Hexavalent chromium (Cr[VI]) is a widespread environmental pollutant in air and water that is primarily attributed to industrial pollution. The current maximum contaminant levels (MCLs) for drinking water from the World Health Organization and the U.S. Environmental Protection Agency (0.05 and 0.1 mg/L, respectively) were set based on contact dermatitis and warrant further toxicological investigation. While Cr(VI) is neurotoxic and accumulates in the brain, most animal studies only report whole-brain Cr, leaving large knowledge gaps. Few studies consider differences between ages or sexes, and fewer consider essential metal dyshomeostasis. We sought to investigate where Cr accumulates in the brain, considering sex and age differences, following a 90-day drinking water exposure to current MCLs. Here, we report Cr levels in six brain regions of rats exposed to drinking water Cr(VI). We observed Cr only accumulated in the hippocampus, and only in older females. We further assessed changes to essential metals in the hippocampus, observing opposite effects across sexes and between young rats compared to older rats. In sum, our data indicate drinking water Cr(VI) selectively targeted the hippocampus, with geriatric females accumulating the most Cr, and induced significant essential metal dyshomeostasis even in tissues lacking evident Cr accumulation.
