Multiple stressor effects of radiation and metals in salmon ( Salmo salar)

Abstract

These experiments were designed to look at the cellular effects in key organs in Atlantic salmon ( Salmo salar) after exposure in vivo to radiation and subtoxic levels of aluminum (Al) and cadmium (Cd), alone or in combination. Salmon (25 g) were exposed to a single 0.5 Gy dose of γ-irradiation in water containing Cd, Al or Cd + Al. Three fish per group were sacrificed after 1 h and the liver, pronephros, fin and gill of each was dissected. Small explants of each tissue were set up. After 2 days, the culture medium was harvested and filtered then placed on a reporter cell line for determination of stress signal activity (bystander effects). Radiation in combination with Cd and/or Al, caused bystander effects in tissues harvested from in vivo exposed salmon. The effects vary between different organs and are not consistently additive or synergistic for a given treatment. Tissue type appears to be critical. Liver cultures produce a toxic factor which is lethal to reporter cells, and therefore no liver data could be obtained. It is hoped that this stress signal response will prove to be a useful indicator of environmental stress in species inhabiting aquatic ecosystems.