Interactive effects of chronic waterborne copper and cadmium exposure on tissue-specific metal accumulation and reproduction in fathead minnow (Pimephales promelas).
The present study was carried out to examine the interactive effects of chronic waterborne copper (Cu) and cadmium (Cd) on tissue-specific metal accumulation and reproduction in fathead minnow (Pimephales promelas). Trios (1 male: 2 female; n=5) of fish were exposed for 21days to: (i) control (no added Cu or Cd), (ii) waterborne Cu (75μg/L), (iii) waterborne Cd (5μg/L), and (iv) Cu and Cd mixture (75 and 5μg/L, respectively). Reproductive output (cumulative egg production) was significantly reduced by Cu but not by Cd. Interestingly however, no spawning occurred in fish exposed to the mixture of waterborne Cu and Cd. In general, both Cu and Cd accumulation in target tissues (gill, liver, gonad and carcass) increased significantly in fish exposed to Cu and Cd mixture, and no interaction between Cu and Cd accumulation was observed in any tissues, except in the liver where Cu accumulation was significantly reduced by Cd. The expression of female hepatic estrogen receptor genes (ER-α and ER-β) was most significantly elevated in fish exposed to Cu and Cd mixture, whereas vitellogenin gene expression was reduced maximally in the same exposure. Similarly, the hepatic expression of the metallothionein gene was most significantly upregulated in fish exposed to Cu and Cd mixture. Moreover, the circulating estradiol level in females was significantly decreased only during the co-exposure of waterborne Cu and Cd. Overall, the present study indicates that the interaction of chronic waterborne Cu and Cd exposure may elicit greater than additive effect on reproductive output in fish.
Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada.
Melissa K
MK
Driessnack
Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada.
Amber L
AL
Matthews
Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada.
Jason C
JC
Raine
Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada; Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, Canada. Electronic address: som.niyogi@usask.ca.
Som
S
Niyogi
D000818:Animals; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity*; D003300:Copper / Q000378:metabolism* / Q000633:toxicity*; D003530:Cyprinidae; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D008297:Male; D008670:Metals / Q000378:metabolism / Q000633:toxicity; D009928:Organ Specificity / Q000187:drug effects / Q000502:physiology; D012098:Reproduction / Q000187:drug effects* / Q000502:physiology; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
D008670:Metals; D014874:Water Pollutants, Chemical; D002104:Cadmium; D003300:Copper
Cadmium; Copper; Fathead minnow; Interaction; Metal accumulation; Reproduction