Author(s):
Teixeira, Francisco B ; Oliveira, Ana C. A. de ; Le?o, Luana K. R ; Fagundes, Nath?lia C. F ; Fernandes, Rafael M ; Fernandes, Luanna M. P ; Silva, M?rcia C. F. da ; Amado, Lilian L ; Sagica, Fernanda do Espirito Santo ; Oliveira, Edivaldo Herculano Correa de ; Crespo-Lopez, Maria E ; Maia, Cristiane S. F ; Lima, Rafael R
Date: 2018
Origin: Oasisbr
Subject(s): Cloreto de Merc?rio / toxicidade; Intoxica??o por Merc?rio; Sistema Nervoso Central; C?rtex Motor / anatomia & histologia; Apoptose; Estresse Oxidativo
Description
This work was supported by Pr?-Reitoria de Pesquisa da UFPA (PROPESP, UFPA, Brazil).
Federal University of Par?. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Bel?m, PA, Brazil.
Federal University of Par?. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Bel?m, PA, Brazil.
Federal University of Par?. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Bel?m, PA, Brazil.
Federal University of Par?. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Bel?m, PA, Brazil.
Federal University of Par?. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Bel?m, PA, Brazil.
Federal University of Par?. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Bel?m, PA, Brazil.
Federal University of Par?. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Bel?m, PA, Brazil.
Federal University of Par?. Institute of Biological Sciences. Laboratory of Ecotoxicology. Bel?m, PA, Brazil.
Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Laborat?rio de Cultura de Tecidos e Citogen?tica. Ananindeua, PA, Brasil.
Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Laborat?rio de Cultura de Tecidos e Citogen?tica. Ananindeua, PA, Brasil.
Federal University of Par?. Institute of Biological Sciences. Laboratory of Molecular Pharmacology. Bel?m, PA, Brazil.
Federal University of Par?. Institute of Health Science. Pharmacy Faculty. Laboratory of Inflammation and Behavior Pharmacology. Bel?m, PA, Brazil.
Federal University of Par?. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Bel?m, PA, Brazil.
Mercury is a toxic metal that can be found in the environment in three different forms ? elemental, organic and inorganic. Inorganic mercury has a lower liposolubility, which results in a lower organism absorption and reduced passage through the blood? brain barrier. For this reason, exposure models that use inorganic mercury in rats in order to evaluate its effects on the central nervous system are rare, especially in adult subjects. This study investigated if a chronic exposure to low doses of mercury chloride (HgCl2), an inorganic form of mercury, is capable of promoting motor alterations and neurodegenerative in the motor cortex of adult rats. Forty animals were exposed to a dose of 0.375 mg/kg/day, for 45 days. They were then submitted to motor evaluation and euthanized to collect the motor cortex. Measurement of mercury deposited in the brain parenchyma, evaluation of oxidative balance, quantification of cellular cytotoxicity and apoptosis and density of mature neurons and astrocytes of the motor cortex were performed. It was observed that chronic exposure to inorganic mercury caused a decrease in balance and fine motor coordination, formation of mercury deposits and oxidative stress verified by the increase of lipoperoxidation and nitrite concentration and a decrease of the total antioxidant capacity. In addition, we found that this model of exposure to inorganic mercury caused cell death by cytotoxicity and induction of apoptosis with a decreased number of neurons and astrocytes in the motor cortex. Our results provide evidence that exposure to inorganic mercury in low doses, even in spite of its poor ability to cross biological barriers, is still capable of inducing motor deficits, cell death by cytotoxicity and apoptosis, and oxidative stress in the motor cortex of adult rats.
