COMBINED TOXIC EFFECT OF IRANIAN HEAVY CRUDE OIL AND BACTERIAL CHALLENGES (STREPTOCOCCUS INIAE) ON THE BIOTRANSFORMATION AND INNATE IMMUNE RESPONSES IN ROCKFISH

Abstract

The Hebei Spirit oil spill is one of the largesttanker spills in recent years. The released and residual crude oil exposedto coastal fish by many routes of exposure and could pass directlythrough the plasma membrane. It can be expected that the lethal andsublethal effects through the induction of metabolites and disruption ofimmune systems. To clarify the relation to the effects of spilled crude oilon fish bacterial disease resistance, combined exposure to Iranian HeavyCrude Oil (IHCO) and S. iniae were conducted. Hepaticbiotransformation enzymes (EROD, GST) and plasma biochemicalparameters (GOT, GPT, GLU) in fish exposed to IHCO were nosignificant difference than those of unexposed fish. But the level ofbiliary 1-OH-pyrene and CYP1A mRNA expression increased IHCOdose-dependently. The interferon stimulated gene 15, interleukin-1betaand cathepsin L were increased significantly in the liver, but thegranulocyte colonystimulating factor was not related to concentration ofIHCO exposure. Percentage of mortality in fish from combinedexposure to IHCO was showed positive correlation with concentrationof IHCO exposure. Hence, we suggested that IHCO could be enhancingto fish mass mortality by environmental bacterial infection. Therefore,the potential immune disturbances in fish exposed to IHCO may allowaffect the bacterial disease resistance.d that the lethal andsublethal effects througd that the lethal andsublethal effects through the induction of metabolites and disruption ofimmune systems. To clarify the relation to the effects of spilled crude oilon fish bacterial disease resistance, combined exposure to Iranian HeavyCrude Oil (IHCO) and S. iniae were conducted. Hepaticbiotransformation enzymes (EROD, GST) and plasma biochemicalparameters (GOT, GPT, GLU) in fish exposed to IHCO were nosignificant difference than those of unexposed fish. But the level ofbiliary 1-OH-pyrene and CYP1A mRNA expression increased IHCOdose-dependently. The interferon stimulated gene 15, interleukin-1betaand cathepsin L were increased significantly in the liver, but thegranulocyte colonystimulating factor was not related to concentration ofIHCO exposure. Percentage of mortality in fish from combinedexposure to IHCO was showed positive correlation with concentrationof IHCO exposure. Hence, we suggested that IHCO could be enhancingto fish mass mortality by environmental bacterial infection. Therefore,the potential immune disturbances in fish exposed to IHCO may allowaffect the bacterial disease resistance.d that the lethal andsublethal effects throug