ALTERATION OF DISSOLVED CADMIUM AND ZINC UPTAKE KINETICS BY METAL PRE-EXPOSURE IN THE BLACK SEA BREAM (ACANTHOPAGRUS SCHLEGELI)

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

40 Scopus Citations
View graph of relations

Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)1312-1321
Journal / PublicationEnvironmental Toxicology and Chemistry
Volume25
Issue number5
Publication statusPublished - May 2006
Externally publishedYes

Abstract

We first examined the uptake kinetics of Cd and Zn in the juvenile marine black sea bream (Acanthopagrus schlegeli) over a wide range of ambient Cd and Zn concentrations, and the relationships with metal accumulation (uptake rate and amount of nonexchangeable surface binding) were established for different fish tissues. Both Cd and Zn accumulation in the body increased linearly with exposure time after the initial metal surface binding. The dissolved Cd and Zn uptake rate constants were 2.64 and 6.50 L/kg/d, respectively, and the kinetics followed a first-order process. No evidence of biphasic transport was found, in contrast to the situation in freshwater fish. Viscera were the most important sites of metal uptake, and gills were the second most important sites. The black sea breams were then acclimated at different Cd or Zn concentrations from either waterborne or dietary source for one week, and the alteration of metal uptake kinetics or subcellular distribution and metallothionein (MT) induction were further quantified. The Cd body burden was enhanced up to 8.6- and 49-fold after waterborne and dietary Cd pre-exposure, respectively. Cadmium pre-exposure also altered the tissue-specific subcellular Cd distribution and significantly elevated tissue MT levels. In contrast, the black sea breams were able to regulate Zn accumulation, and waterborne or dietary Zn pre-exposure had only weak influences on Zn body burden and redistribution. Both Cd and Zn pre-exposures enhanced the metal uptake rate constants, whereas the nonexchangeable surface bindings were less impacted by these pre-exposures. We demonstrated a positive relationship between the Cd uptake rate and Cd or MT concentration in the fish. Pre-exposure to metals may substantially modify the kinetics of metal uptake. © 2006 SETAC.

Research Area(s)

  • Cadmium, Marine fish, Metal uptake, Pre-exposure, Zinc