Cope, W. G., Wiener, J. G., and Atchison, G. J., 1994, Hepatic cadmium,
metal-binding proteins and bioaccumulation in bluegills exposed to aqueous
cadmium: Environmental Toxicology and Chemistry, v. 13, no. 4, p. 553-562.

Abstract

We examined sublethal responses of juvenile bluegills Lepomis macrochirus to
aqueous cadmium in two 28-d tests (test I, 0.0-8.4 mu g per liter; test II, 0.0-32.3
mu g Cd per liter) in an intermittent-flow diluter. The experimental design was
completely randomized, with two replicates in each of eight treatments (seven Cd
exposures and one water control with 25 fish per replicate). Cadmium did not
affect the growth of test fish. The mean whole-body concentrations of Cd in
exposed fish were 1.8- to 44-fold those in controls in the two tests. Mean
concentrations of hepatic nonthionein cytosolic Cd (not bound by metal-binding
proteins, MBP) in all Cd treatments greatly exceeded those in controls, and mean
concentrations of hepatic MBP in all treatments except one (0.8 mu g Cd per liter
in test I) exceeded those in controls. Nonthionein cytosolic Cd, hepatic MBP, and
whole-body Cd in bluegills were linearly related to exposure concentrations within
the range 0 to 20 mu g Cd per liter. Much of the total Cd-binding capacity of
hepatic MBP per fish was occupied by Cd after the 28-d exposures, although
additional Cd-binding capacity remained unoccupied by Cd in fish in all
treatments. The mean total Cd-binding capacity of hepatic MBP per fish, which
ranged from 1.7 to 14 nmol Cd in test I and from 0.8 to 24 nmol Cd in test II,
increased in a concentration-response manner at exposure concentrations below 13
mu g/L. Nonthionein cytosolic Cd was the most sensitive indicator of Cd exposure,
based on an LOEC of 0.8 mu g Cd per liter.

Keywords

water-pollution-effects, bioaccumulation-, bluegills-, toxicity-, cadmium-,
proteins-, sublethal-effects, tissue-analysis, Lepomis-macrochirus, toxicity-testing,
pollution-effects, liver-, metal-binding-protein, heavy- metals, water-pollution,
fish-physiology, freshwater-fish