Bone manganese (Mn) concentrations in Sprague-Dawley rats following subchronic manganese exposure

Details

• Personal Author:
  Hong L ; Neal SO ; Nie L ; Zheng W
• Description:
  Occupational exposure to manganese (Mn) causes a Parkinson-type disorder called Manganism, a neurodegenerative disease currently without reliable biomarkers for body burden estimation and for pre-symptomatic toxicity assessment. Data in literature suggest that Mn deposited in bone accounts for 43% of total body Mn. The objective of this study was to determine if bone Mn levels were parallel to Mn concentrations in brain regions known to be the targets of Mn toxicity. Groups of rats (6-7 each) received daily dose of 50 mg Mn/kg as MnCl2 PO for 0, 2, 4, 6, 8 or 10 weeks before tissue dissection. The metal concentrations of Mn, zinc (Zn), iron (Fe), and copper (Cu) in bone tissues, body fluids, brain tissues, as well as other organs were analyzed by atomic absorption spectrophotometry. Following Mn exposure, bone tissues including femur, tibia, humerus and skull bones showed a dose-time-dependent increase in Mn concentrations, with 1.0-1.6 microg/g of bone mass at week 10, which were about 2.3-3.6 fold higher than those in controls (approximately 0.4 microg/g) at day 0 (p<0.01). A statistically significant relationship exists between bone Mn concentrations and Mn levels in brain tissues such as striatum (r=0.755, p<0.001), hippocampus (r=0.782, p<0.001) and choroid plexus (0.652, p<0.001), and in brain fluid such as cerebrospinal fluid (r=0.720, p<0.001). Interestingly, in vivo exposure to Mn also led to significantly increased Fe (152-372%) and Zn (194-230%) concentrations in bone tissues except the skull bones, with no statistically significant effect on bone Cu (58-95%). These results suggest that bone is a significant storage site for body Mn; the good correlation between bone Mn and brain Mn alludes to bone Mn being an internal source of Mn long-term exposure. Further experimentation for noninvasive quantitation of Mn in bone is well warranted for Mn neurotoxicological research. [Description provided by NIOSH]
• Subjects:
  Body Fluids Laboratories Manganese Metals Musculoskeletal System Nervous System Occupational Health Safety Toxicology
• Keywords:
  Author Keywords: Manganese Biomarker Body-burden Body-fluids Body-regions Bone Bone-structure Brain-matter Correlation Dose-response Exposure-levels In-vivo-study Laboratory-animals Manganese-compounds Manganism Metal-compounds Neurological-system Neurophysiological-effects Neurotoxic-effects Neurotoxicology Pharmacodynamics Pharmacokinetics Tissue-culture

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• ISSN:
  1096-6080
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Indiana ; OSHA Region 5 ; OSHA Region 6 ; Texas
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  132
• Issue:
  1
• NIOSHTIC Number:
  nn:20042439
• Citation:
  Toxicologist 2013 Mar; 132(1):396
• CAS Registry Number:
  Copper (CAS RN 7440-50-8) ; Iron (CAS RN 7439-89-6) ; Manganese (CAS RN 7439-96-5) ; Zinc (CAS RN 7440-66-6)
• Federal Fiscal Year:
  2013
• Performing Organization:
  Purdue University, West Lafayette, Indiana
• Peer Reviewed:
  False
• Start Date:
  20120701
• Source Full Name:
  The Toxicologist. Society of Toxicology 52nd Annual Meeting and ToxExpo, March 10-14, 2013, San Antonio, Texas
• End Date:
  20150630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9b986680430c38bc99e38c0b58f499e4e9b57880c8116eee425833703bc5d0b00e8622a7e8b8d0e2377ebc492c74eefd65e6dec05638d114ccad5d1dd1c5c624
• Download URL:
  https://stacks.cdc.gov/view/cdc/194663/cdc_194663_DS1.pdf
• File Type:
  [PDF - 583.12 KB ]