Biochemical and physiological responses in liver and muscle of rainbow trout after long-term exposure to propiconazole

Abstract

In this study, the chronic toxic effects of PCZ, a triazole fungicide commonly present in surface and ground water, on morphological indices, ROS generation and RNA/DNA ratio in liver and white muscle of rainbow trout were investigated. Fish were exposed at sublethal concentrations of PCZ (0.2, 50 and 500μgL−1) for 7, 20 and 30d. Compared with the control, there were significant lower CF and HSI in fish exposed at the highest concentration of PCZ. ROS levels in both tissues increased significantly at higher PCZ concentrations (50 and 500μgL−1) after 20d and above, as well as in muscle of fish exposed at lowest PCZ concentration (0.2μgL−1) after 30d. The hepatic antioxidant enzymes (SOD and CAT) activities were induced significantly at higher concentrations (50, 500μgL−1) of PCZ after 20d and at 50μgL−1 after 30d. Additional, hepatic SOD activity was significantly induced at 0.2μgL−1 after 30d. Compared with the hepatic antioxidant enzymes activities in fish exposed to 50μgL−1 of PCZ, there was a decreasing trend in those exposed to 500μgL−1 after 30d exposure. However, both the antioxidant enzymes activities were significantly inhibited in muscle of fish exposed to 500μgL−1 PCZ after 30d. Moreover there was significant lower RNA/DNA ratio in both tissues after long-term exposure to higher concentration of PCZ. In short, environmental concentrations of PCZ could not induce obvious impacts on fish, but long-term exposure to higher concentrations of CBZ could affect seriously the health status of fish.