Brain CYP1A in seabream, Sparus aurata exposed to benzo(a)pyrene.

Full Abstract

This study compares basal and induced expression of cytochrome P4501A-CYP1A in the brain of gilthead seabream, Sparus aurata. Larval or adult seabream were exposed to benzo(a)pyrene -B(a)P- and the CYP1A response was assessed by analyzing CYP1A mRNA (RT-PCR), CYP1A protein (expression levels: ELISA, western blotting; cellular localization: immunohistochemistry), and CYP1A catalytic activity (7-ethoxyresorufin-O-deethylase-EROD). In the brain of adult S. aurata, CYP1A immunostaining was generally detected in the vasculature. It was present in the neuronal fibers and glial cells of the olfactory bulbs and the ventral telencephalon. ELISA and RT-PCR analyses confirmed CYP1A expression in the brains of non-exposed seabream. B(a)P exposure led to increased CYP1A staining mainly in neuronal fibers and glial cells of the olfactory bulbs, but also in the vascular endothelia. EROD activity, however, could not be detected in the brain of adult seabream, neither in control nor in exposed fish. In the developing brain of S. aurata larvae, immunohistochemical staining detected CYP1A protein exclusively in endothelia of the olfactory placode and in retina. Staining intensity of CYP1A slightly increases with larval development, especially in vascular brain endothelia. Exposing the larvae to 0.3 or 0.5 microg B(a)P/L from hatching until 15 days post hatching (dph) did not result in enhanced CYP1A immunostaining in the brain. In samples of whole seabream larvae, both from controls and BaP treatments, neither CYP1A mRNA, protein nor catalytic activity were detectable. The results demonstrate that CYP1A is expressed already and inducible in the larval brain, but that the regional and cellular expression differs partly between larval and adult brain. This may have implications for the toxicity of CYP1A-inducing xenobiotics on early and mature life stages of seabream.

Author information

Author/s: Ortiz-Delgado, J B (JB); Segner, H (H); Sarasquete, C (C);

Affiliation: Institute of Marine Sciences of Andalusia, CSIC, Campus Universitario Río San Pedro, Cádiz, Spain.

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Histology and histopathology (Histol Histopathol), published in Spain. (Language: eng)

Reference: 2009-Oct; vol 24 (issue 10) : pp 1263-73

Dates: Created 2009/08/18; Completed 2009/11/03;

PMID: 19688694, status: MEDLINE (last retrieval date: 11/3/2009, IMS Date: )

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