Methylmercury alters the number and topography of NO-synthase positive neurons in embryonic retina: Protective effect of alpha-tocopherol.

Autor: Sampaio GSA; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil., Oliveira KRHM; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil., Kauffmann N; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil., do Nascimento JLM; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil; Universidade Ceuma, São Luís, Maranhão, Brazil., Souza GS; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brazil., Gomes BD; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil., de Lima SMA; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil., Silveira LCL; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brazil; Universidade Ceuma, São Luís, Maranhão, Brazil., Rocha FAF; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil., Herculano AM; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil. Electronic address: herculano@ufpa.br.
Jazyk: angličtina
Zdroj: Toxicology in vitro : an international journal published in association with BIBRA [Toxicol In Vitro] 2018 Dec; Vol. 53, pp. 89-98. Date of Electronic Publication: 2018 Jul 31.
DOI: 10.1016/j.tiv.2018.07.018
Abstrakt: Vertebrate retina has been shown to be an important target for mercury toxicity and very studies have shown the effect of mercury on the retinal ontogenesis. The nitrergic system plays an important role in the retinal development. The current work studied the effects of methylmercury (MeHg) exposure on the NO-synthase positive neurons (NADPH-diaphorase neurons or NADPH-d+) of the chick retinal ganglion cell layer at embryonic E15 and postnatal P1 days. Retinal flat mounts were stained for NADPH-diaphorase histochemistry and mosaic properties of NADPH-d + were studied by plotting isodensity maps and employing density recovery profile technique. It was also evaluated the protective effect of alpha-tocopherol treatment on retinal tissues exposed to MeHg. MeHg exposure decreased the density of NADPH-d + neurons and altered cell mosaic properties at E15 but had very little or no effect at P1 retinas. Alpha-tocopherol has a protective effect against MeHg exposure at E15. MeHg alterations and alpha-tocopherol protective effect in embryonic retinas were demonstrated to be at work in experimental conditions. MeHg effect in the early phases of visual system development in natural conditions might use the nitrergic pathway and supplementary diet could have a protective effect. At later stages, this mechanism seems to be naturally protected.
(Copyright © 2018. Published by Elsevier Ltd.)
Databáze: MEDLINE
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