Premium
Acclimation‐induced changes in toxicity and induction of metallothionein‐like proteins in the fathead minnow following sublethal exposure to zinc
Author(s) -
Hobson James F.,
Birge Wesley J.
Publication year - 1989
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620080207
Subject(s) - metallothionein , toxicity , pimephales promelas , minnow , acclimatization , glutathione , acute toxicity , toxicokinetics , chemistry , zinc , ecotoxicology , zoology , population , bioaccumulation , cyprinidae , biology , toxicology , biochemistry , environmental chemistry , fish <actinopterygii> , ecology , demography , sociology , organic chemistry , fishery , enzyme
Experiments were conducted to determine if a correlation exists between acclimation‐induced alterations in Zn toxicity and the concentration of metallothionein‐like proteins (MTP) in a cyprinid fish. Populations of subadult fathead minnows, Pimephales promelas , were maintained in dechlorinated tap water and exposed to 0, 0.60 and 1.80 mg Zn/L for 35 d. Groups of animals (120 each) were removed from each acclimation population after 0, 7, 14, 21 and 35 d to conduct 96‐h acute tests. Tolerance and resistance were monitored as changes in the 96‐h LC50 and LT50 values, respectively. Tolerance increased a significant 28% above control values after 14 d of exposure to 0.60 mg Zn/L, but decreased significantly to 63 and 74% of control values following exposure to 1.80 mg Zn/L for 7 and 14 d ( p < 0.05). Acute toxicity values returned to control levels in both treatment groups after 21 d of exposure and remained stable to 35 d. The concentration of MTP was measured in the viscera (i.e., liver, spleen, intestine and pancreas) indirectly as the total Zn‐binding capacity in MTP‐containing fractions. MTP levels increased after 7, 14 and 21 d and plateaued to 35 d. Metal concentration in the MTP fraction reached a maximum of 31.6 μg Zn/g viscera, and following 28 d of exposure to 1.80 mg Zn/L concentrations declined to control levels after 7 d in diluent water. Whole‐body residues of Zn reached steady state after 7 d of exposure to 0.60 mg Zn/L but continued to increase after 35 d of exposure to 1.80 mg Zn/L. Zn‐acclimated animals were cross‐resistant but not cross‐tolerant to acute Cd challenge. There was no correlation of alterations in toxicity with observed changes in MTP concentration. Growth effects were observed at both acclimation exposure levels.