Modulation of uranium bioaccumulation by hypoxia in the freshwater clam Corbicula fluminea: Induction of multixenobiotic resistance protein and heat shock protein 60 in gill tissues

Tran, D. (a) , Bourdineaud, J.-P.(b) , Massabuau, J.-C.(b) , Garnier-Laplace, J.(a)
Environmental Toxicology and Chemistry
Volume 24, Issue 9, 2005, Pages 2278-2284

The influence of hypoxia on the bioaccumulation of uranium in the clam Corbicula fluminea was investigated in ecologically relevant conditions. The cellular impact at the gill-tissue level was assessed by analyzing the induction of multixenobiotic resistance protein (MXR) and heat shock protein 60. Analyses were performed at three biological levels. First, at the organism level, uranium induced a significant decrease in the valve open duration under normoxia, but not under hypoxia, in which oxygen drive imposed an increase of the valve open duration. Second, at the tissue level, the uranium bioaccumulation rate in the gills was higher under hypoxia than under normoxia. Third, at the cellular level, MXR was induced by uranium but not by hypoxia. The threshold of tissular uranium concentration triggering MXR induction was between 3 and 5 nmol/g. On the contrary, Hsp60 was induced by hypoxia but not by uranium.The influence of hypoxia on the bioaccumulation of uranium in the clam Corbicula fluminea was investigated in ecologically relevant conditions. The cellular impact at the gill-tissue level was assessed by analyzing the induction of multixenobiotic resistance protein (MXR) and heat shock protein 60. Analyses were performed at three biological levels. First, at the organism level, uranium induced a significant decrease in the valve open duration under normoxia, but not under hypoxia, in which oxygen drive imposed an increase of the valve open duration. Second, at the tissue level, the uranium bioaccumulation rate in the gills was higher under hypoxia than under normoxia. Third, at the cellular level, MXR was induced by uranium but not by hypoxia. The threshold of tissular uranium concentration triggering MXR induction was between 3 and 5 nmol/g. On the contrary, Hsp60 was induced by hypoxia but not by uranium.

a/ Laboratoire de Radioécologie et Ecotoxicologie, Institut de Radioprotection et de Sûreté Nucléaire, Batiment 186, BP3, 13115 Saint Paul-Lez-Durance, Cedex, France
b/ Laboratoire d'Ecophysiologie et Ecotoxicologie des Systèmes Aquatiques, Université Bordeaux 1, Comité National de la Recherche Scientifique, Place du Dr. Peyneau, 33120 Arcachon, France