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de Oliveira Lopes G, Aragão WAB, Bittencourt LO, Puty B, Lopes AP, Dos Santos SM, Monteiro MC, de Oliveira EHC, da Silva MCF, Lima RR. Imaging Microstructural Damage and Alveolar Bone Loss in Rats Systemically Exposed to Methylmercury: First Experimental Evidence. Biol Trace Elem Res 2021; 199:3707-3717. [PMID: 33409908 DOI: 10.1007/s12011-020-02492-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/12/2020] [Indexed: 10/22/2022]
Abstract
The alveolar bone is an important mineralized structure of the periodontal support apparatus, and information about the methylmercury (MeHg) effects on the structural integrity is scarce. Therefore, this study aimed to investigate whether systemic, chronic, and low-dose exposure to MeHg can change the alveolar bone microstructure of rats. Adult Wistar rats (n = 30) were exposed to 0.04 mg/kg/day of MeHg or vehicle through intragastric gavage. The animals were euthanized after 60 days, and blood samples were collected for trolox equivalent antioxidant capacity (TEAC), glutathione (GSH), lipid peroxidation (LPO), and comet assays. The mandible of each animal was collected and separated into hemimandibles that were used to determine the total Hg level in the bone and to analyze microstructural damage and alveolar bone loss in terms of trabecular number (Tb.N), trabecular thickness (Tb.Th), bone volume fraction (BV/TV), and exposed root area of the second molars. MeHg exposure triggered oxidative stress in blood represented by lower levels of GSH and TEAC and the increase in LPO and DNA damage of the blood cells. High total Hg levels were found in the alveolar bone, and the microstructural analyses showed a reduction in Tb.N, Tb.Th, and BV/TV, which resulted in an increase in the exposed root area and a decrease in bone height. Long-term MeHg exposure promotes a systemic redox imbalance associated with microstructural changes and alveolar bone loss and may indicate a potential risk indicator for periodontal diseases.
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Affiliation(s)
- Géssica de Oliveira Lopes
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Augusto Corrêa Street N. 01, Guamá, Belém, Pará, 66075-110, Brazil
| | - Walessa Alana Bragança Aragão
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Augusto Corrêa Street N. 01, Guamá, Belém, Pará, 66075-110, Brazil
| | - Leonardo Oliveira Bittencourt
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Augusto Corrêa Street N. 01, Guamá, Belém, Pará, 66075-110, Brazil
| | - Bruna Puty
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Augusto Corrêa Street N. 01, Guamá, Belém, Pará, 66075-110, Brazil
| | - Armando Pereira Lopes
- School of Dentistry, Institute of Health Sciences, Federal University of Pará, Belém, Brazil
| | - Sávio Monteiro Dos Santos
- Laboratory of Clinical Immunology and Oxidative Stress, Pharmacy Faculty, Institute of Health Sciences, Federal University of Pará, Belém, Brazil
| | - Marta Chagas Monteiro
- Laboratory of Clinical Immunology and Oxidative Stress, Pharmacy Faculty, Institute of Health Sciences, Federal University of Pará, Belém, Brazil
| | - Edivaldo Herculano Corrêa de Oliveira
- Cytogenetics and Tissue Culture Laboratory, Evandro Chagas Institute, Ananindeua, Brazil
- Exact and Natural Sciences Institute, Federal University of Pará, Belém, Brazil
| | - Márcia Cristina Freitas da Silva
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Augusto Corrêa Street N. 01, Guamá, Belém, Pará, 66075-110, Brazil
| | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Augusto Corrêa Street N. 01, Guamá, Belém, Pará, 66075-110, Brazil.
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