Effects of short-term copper exposure on gill structure, metallothionein and hypoxia-inducible factor-1a (HIF-1a) levels in rainbow trout (Oncorhynchus mykiss)
van Heerden, D.; Vosloo, A.; Nikinmaa, M. (2004). Effects of short-term copper exposure on gill structure, metallothionein and hypoxia-inducible factor-1a (HIF-1a) levels in rainbow trout (Oncorhynchus mykiss). Aquat. Toxicol. 69(3): 271-280. http://dx.doi.org/10.1016/j.aquatox.2004.06.002
In: Aquatic Toxicology. Elsevier Science: Tokyo; New York; London; Amsterdam. ISSN 0166-445X; e-ISSN 1879-1514, more
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| Keywords |
Chemical elements > Metals > Transition elements > Heavy metals > Copper
Fishes > Osteichthyes > Salmoniformes > Salmonidae > Salmo > Freshwater fishes > Rainbow trout
Peptides > Proteins > Sulfur proteins > Thioneins > Metalloproteins > Metallothionein
Oncorhynchus mykiss (Walbaum, 1792) [WoRMS]; Oncorhynchus mykiss (Walbaum, 1792) [WoRMS]
Marine/Coastal |
| Author keywords |
copper; rainbow trout; Oncorhynchus mykiss; metallothionein;hypoxia-inducible factor (HIF); gill damage; diffusion distance |
| Authors | | Top |
- van Heerden, D.
- Vosloo, A.
- Nikinmaa, M.
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| Abstract |
Rainbow trout (Oncorhynchus mykiss) were exposed to 1.65 M of waterborne copper for 24 h. Fish were then transferred to metal-free water. Metallothionein mRNA induction in rainbow trout liver and gill tissue, hypoxia-inducible factor-1 (HIF-1a) accumulation in gill tissue and arithmetic mean thickness of gill epithelium (Har) were determined at 4 and 24 h of exposure as well as 48 h after transfer to metal-free water. The arithmetic mean distance from water to blood was significantly elevated after both 4 and 24 h of exposure (Har was 4.67 and 4.66 µm, respectively in exposed fish, compared to 3.81 and 3.62 µm for the corresponding control fish). During the 48 h recovery Har returned towards the control values; the recovery value of 4.21 m was significantly lower than values during exposures. There was also a significant increase in gill metallothionein mRNA levels after the 4 h exposure with MT/GAPDH ratio of 1.288 versus the control value of 0.988. In liver, metallothionein induction was not observed. HIF-1 protein showed an increased accumulation in gills after 4 h, with the HIF-1a/a-tubulin ratio of 0.562 being significantly higher than the 24 h exposure value of 0.232. These results suggest that exposure to copper for four hours causes hypoxia in the gill epithelium, which is adequate for the activation of HIF-1a. |
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