Short-term bioaccumulation, circulation and metabolism of estradiol-17β in the oyster Crassostrea gigas

• Published in: Journal of Experimental Marine Biology and Ecology
• Main Authors: Le Curieux-Belfond, O., Fievet, B., Séralini, G.E., Mathieu, M.
• Other Authors: Laboratoire de Physiologie et Ecophysiologie des mollusques marins, Laboratoire de Radioécologie de Cherbourg-Octeville (IRSN/PSE-ENV/SRTE/LRC), Service de recherche sur les transferts et les effets des radionucléides sur les écosystèmes (IRSN/PSE-ENV/SRTE), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: bioaccumulation; biomarker; bivalve; estrogenic compound; Bivalvia; Crassostrea gigas; Invertebrata; Mollusca; Ostreidae; Pisces; Vertebrata; [SDV]Life Sciences [q-bio]
• Online Access: https://hal.science/hal-03039350; https://doi.org/10.1016/j.jembe.2005.04.027

Steroids are active signal transmitters in Vertebrates. These roles have also been hypothesized in other Phyla and endocrine disrupting effects have been reported for different estrogen-like compounds in fishes and some marine invertebrates. As estradiol-17β has shown some physiological activities in the oyster and as estrogens or estrogen-like molecules can be present in water, we have investigated the bioaccumulation and metabolism of this estrogen in vivo in the oyster Crassostrea gigas. When dissolved in seawater, in less than 48 h estradiol-17β concentrated up to 31 times in the soft tissues of the suspension-feeder mollusc. Injected in the adductor muscle, estradiol-17β circulated from muscle to the gonad, the gills, the mantle, the labial palps, and to a lesser extent to the digestive gland. After 2 h, estradiol flow increased specifically towards this gland. Different hypotheses were raised concerning the circulation paths. However, in all cases estradiol metabolism primarily evidenced an in vivo transformation into estrone in the whole oyster and in its digestive gland. This strong 17β-hydroxysteroid-dehydrogenase activity confirms our previous in vitro results. In conclusion, it is proposed that oyster is able to take in charge estradiol as a potential contaminant in seawater. Therefore, its bioaccumulation and transformation into estrone could be studied as potential biomarkers of endocrine disruption. Furthermore, the experimental approach with dissolved steroids in the seawater combined to an anatomical screening appears as an interesting tool to investigate the bivalve endocrinology. © 2005 Elsevier B.V. All rights reserved.