Effects of inorganic mercury exposure in the alveolar bone of rats: an approach of qualitative and morphological aspects

Paula Beatriz de Oliveira Nunes; Maria Karolina Martins Ferreira; Deborah Ribeiro Frazão; Leonardo Oliveira Bittencourt; Victória Dos Santos Chemelo; Márcia Cristina Freitas Silva; Armando Lopes Pereira-Neto; Alan Rodrigo Leal Albuquerque; Simone Patricia Aranha Paz; Rômulo Simões Angélica; Sofia Pessanha; Rafael Rodrigues Lima

doi:10.7717/peerj.12573

Effects of inorganic mercury exposure in the alveolar bone of rats: an approach of qualitative and morphological aspects

PeerJ. 2022 Jan 26:10:e12573. doi: 10.7717/peerj.12573. eCollection 2022.

Authors

Affiliations

¹ Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Pará, Brazil.
² School of Dentistry, Federal University of Pará, Belém, Pará, Brazil.
³ Institute of Geosciences, Federal University of Pará, Belém, Pará, Brazil.
⁴ Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics, NOVA School of Sciences and Technology, Caparica, Portugal.

Abstract

Background: In comparison to organic mercury (MeHg), the environmental inorganic mercury (IHg) can be found in some skin-lightening cosmestics were considered "harmless" for a long time. However, recent studies have shown that long-term exposure to low doses of IHg may affect biological systems. Therefore, this study investigated the effects of IHg long-term exposure to the alveolar bone of adult rats.

Methods: Adult Wistar rats were distributed in control and HgCl₂ exposed (0.375 mg/kg/day). After 45 days, the rats were euthanized and both blood and hemimandibles were collected. Total blood Hg levels were measured and both inorganic and organic components of the alveolar bone were determined through XRD and ATR-FTIR. The microstructure of the alveolar bone was assessed by using micro-CT and the morphometric analysis was performed by using stereomicroscopy.

Results: Alterations in the physicochemical components of the alveolar bone of exposed animals were observed. The bone changes represented a tissue reaction at the microstructural level, such as bone volume increase. However, no significant dimensional changes (bone height) were observed.

Conclusion: Exposure to IHg at this dose can promote microstructural changes and alteration in the organic and inorganic components in the alveolar bone.

Keywords: Alveolar bone; Infrared mineral characterization; Inorganic mercury; Mercury chloride; Micro-computed tomography; Rats.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Mercury* / toxicity
Rats
Rats, Wistar

Substances

Mercury

Grants and funding

This study was supported by the Pró-Reitoria de Pesquisa (PACI/PROPESP/UFPA/Brazil), Brazilian National Council for Scientific and Technological Development (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES) – Finance Cod 001. The APC was funded by Pró-Reitoria de Pesquisa e Pós-graduação from Universidade Federal do Pará (PROPESP-UFPA). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.