title: Altered transition metal homeostasis in mice following manganese injections for manganese-enhanced magnetic resonance imaging.
abstract: In manganese-enhanced magnetic resonance imaging (MEMRI), the paramagnetic divalent ion of manganese (Mn(2+)) is injected into animals to generate tissue contrast, typically at much higher exposures than have been previously used in studies of Mn toxicity. Here we investigate the effect of these injections on the homeostasis of the transition metals iron and copper in mice to see if there are disruptions which should be considered in MEMRI studies. Manganese shares transport proteins with other transition metals including iron and copper, so it is possible that changes in manganese levels in tissue following injections of the metal may affect other metal levels too. This in turn may affect MRI contrast or the investigation of disease processes in the animal models being imaged. In this study, we measured manganese, iron, and copper concentrations in the blood, kidney, liver and in brain regions in mice treated with four injections of 30 mg/kg MnCl(2) 4H(2)O (dry chemical weight/body weight)-a common dose used in MEMRI. In addition to the expected increases in manganese in tissues, we noted a statistically significant reduction in copper in the kidney and liver. Also, we noted a statistically significant decrease in concentration of iron in the thalamus of the brain. These findings suggest that the high doses of manganese injected in MEMRI studies can disrupt the homeostasis of other transition metals in mice.
authors: Department of Medical Physics and Applied Radiation Sciences, McMaster University, General Sciences Building, Room 105, Hamilton, ON, L8S 4L8, Canada.
authors: Nataliya
authors: N
authors: Moldovan
authors: Alia
authors: A
authors: Al-Ebraheem
authors: Nelson A
authors: NA
authors: Miksys
authors: Michael J
authors: MJ
authors: Farquharson
authors: Nicholas A
authors: NA
authors: Bock
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D003287:Contrast Media / Q000008:administration & dosage* / Q000493:pharmacokinetics; D003300:Copper / Q000378:metabolism*; D006706:Homeostasis; D007501:Iron / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008345:Manganese / Q000008:administration & dosage* / Q000493:pharmacokinetics; D051379:Mice; D008810:Mice, Inbred C57BL; D012015:Reference Standards; D013052:Spectrometry, X-Ray Emission / Q000592:standards; D028561:Transition Elements / Q000378:metabolism
chemical_list: D003287:Contrast Media; D028561:Transition Elements; D008345:Manganese; D003300:Copper; D007501:Iron