Losses of immunoreactive parvalbumin amacrine and immunoreactive alphaprotein kinase C bipolar cells caused by methylmercury chloride intoxication in the retina of the tropical fish Hoplias malabaricus
Braz. j. med. biol. res
; 39(3): 405-410, Mar. 2006. ilus
Article
de En
| LILACS
| ID: lil-421368
Bibliothèque responsable:
BR1.1
ABSTRACT
To quantify the effects of methylmercury (MeHg) on amacrine and on ON-bipolar cells in the retina, experiments were performed in MeHg-exposed groups of adult trahiras (Hoplias malabaricus) at two dose levels (2 and 6 µg/g, ip). The retinas of test and control groups were processed by mouse anti-parvalbumin and rabbit anti-alphaprotein kinase C (alphaPKC) immunocytochemistry. Morphology and soma location in the inner nuclear layer were used to identify immunoreactive parvalbumin (PV-IR) and alphaPKC (alphaPKC-IR) in wholemount preparations. Cell density, topography and isodensity maps were estimated using confocal images. PV-IR was detected in amacrine cells in the inner nuclear layer and in displaced amacrine cells from the ganglion cell layer, and alphaPKC-IR was detected in ON-bipolar cells. The MeHg-treated group (6 µg/g) showed significant reduction of the ON-bipolar alphaPKC-IR cell density (mean density = 1306 ± 393 cells/mm²) compared to control (1886 ± 892 cells/mm²; P < 0.001). The mean densities found for amacrine PV-IR cells in MeHg-treated retinas were 1040 ± 56 cells/mm² (2 µg/g) and 845 ± 82 cells/mm² (6 µg/g), also lower than control (1312 ± 31 cells/mm²; P < 0.05), differently from the data observed in displaced PV-IR amacrine cells. These results show that MeHg changed the PV-IR amacrine cell density in a dose-dependent way, and reduced the density of alphaKC-IR bipolar cells at the dose of 6 µg/g. Further studies are needed to identify the physiological impact of these findings on visual function.
Texte intégral:
1
Collection:
01-internacional
Base de données:
LILACS
Sujet principal:
Parvalbumines
/
Cellules amacrines
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Cellules bipolaires rétiniennes
/
Protein kinase C-alpha
/
Poissons
/
Composés méthylés du mercure
Type d'étude:
Prognostic_studies
Limites:
Animals
Langue:
En
Journal:
Braz. j. med. biol. res
Sujet du journal:
BIOLOGIA
/
MEDICINA
Année:
2006
Type de document:
Article
/
Congress and conference
/
Project document
Pays d'affiliation:
Brésil
Pays de publication:
Brésil