Tissue-specific effects of acute aluminium exposure on the radiation-induced bystander effect in rainbow trout (Oncorhynchus mykiss, Walbaum)

Abstract

Purpose: To investigate if aluminium (Al) modifies the rainbow trout response to radiation exposure and/or the induction of a radiation-induced bystander effect.

Methods: Rainbow trout were exposed to 100 or 200 μg l⁻¹ Al (for 3 h), a 0.5 Gy X-ray dose or Al followed immediately by irradiation. The exposed fish were then swum with completely untreated bystander fish. A human reporter cell clonogenic assay was used to determine whether Al exposure modified the effects of irradiation on the skin and gills from directly exposed fish and also the radiation-induced bystander effect in untreated fish.

Results: Al exposure did not modify the response to direct irradiation by the skin, or the gill. Al did not modify the bystander effect in the skin. However Al did modify the bystander effect in the gill. Gills of bystander fish swum with fish exposed to 200 μg l⁻¹ Al, followed by irradiation, caused a greater reduction in HPV-G cell survival than was caused by irradiation only. Interestingly Al exposure only also caused a bystander effect (reduced HPV-G survival) in the gill.

Conclusion: This study shows that, in a multiple stressor scenario, the communication of radiation-induced stress signals is modified on a tissue-specific basis by acute Al exposure. Aside from the implications this has for radiological protection this response may also have potential for environmental monitoring where detection of the bystander effect could act as an indicator of radiation exposure when direct exposure responses are not evident.

Keywords::

• Aluminium
• multiple stressor
• bystander effect
• fish radiobiology

Acknowledgements

We acknowledge funding from the Natural Sciences and Engineering Research Council (NSERC) Industrial Chairs Research Programme, Canada Deuterium Uranium (CANDU) Owners Group, Bruce Power, The Canada Chairs Programme. We also acknowledge our participation as non-funded third country partners in the European Union's Non-Targeted Effects integrated project (NOTE). Finally we would like to express our grateful thanks to Michael Burke, David Bevan, Michael Kirk and Neil MacBeth, Alma Aquaculture Research Station, University of Guelph, for the rearing and husbandry of all of the fish used in this investigation.

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.