Concentrations of Copper-Binding Proteins in Livers of Bluegills Exposed to Increased Concentrations of Soluble Copper.

摘要

Previous data on copper in liver metalloproteins of bluegills from the cooling lake at the H.B. Robinson Nuclear Power Station indicated that labile copper released from the cooling system may be responsible for the increased deformities and reduced reproductive capacity of the bluegills. Experiments were conducted to determine the concentrations of copper in effluents and the durations of chronic exposure to sublethal levels of copper that bluegills can tolerate without adverse effects. Groups of young bluegills were exposed to water regulated to pH 5.5 that contained either no additional copper or 20, 40, 80, or 160 micrograms/l additional copper. In one tank, water was regulated to pH 7 and the copper to 80 micrograms/l. Liver metalloproteins from the bluegills were separated into a low molecular-weight (LMW) protein fraction, which contains metallothioneins (MTs), and into intermediate molecular-weight (IMW) and high molecular-weight (HMW) fractions, which contain metalloenzymes (MEs), using high performance liquid chromatography. Large differences in quantities of copper associated with metalloproteins were found. Mortality was dependent on exposure concentration and duration and appeared to be related to the exceeding of the MT-detoxification capability.