Toxic Effects of Cadmium on Fish

Abstract

Large amounts of enriched cadmium (Cd) in the environment seriously threatens the healthy and sustainable development of the aquaculture industry and greatly restricts the development of the food processing industry. Studying the distribution and toxic effects of Cd in fish, as well as the possible toxic effects of Cd on the human body, is very significant. A large number of studies have shown that the accumulation and distribution of Cd in fish are biologically specific, cause tissue differences, and seriously damage the integrity of tissue structure and function, the antioxidant defense system, the reproductive regulation system, and the immune system. The physiological, biochemical, enzyme, molecular, and gene expression levels change with different concentrations and times of Cd exposure, and these changes are closely related to the target sites of Cd action and tissues in fish. Therefore, the toxic effects of Cd on fish occur with multiple tissues, systems, and levels.

Keywords: aquatic ecosystems; cadmium accumulation; cadmium toxicity; food chain; oxidative stress.

Figure 1

Schematic diagram of toxic effects of Cd on fish organs.

Figure 2

Schematic diagram of ROS metabolism and oxidative stress induced by Cd. Under normal physiological conditions, the ROS in the body are mainly converted into less toxic or harmless substances by antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), while under the condition of Cd exposure, a large amount of ROS are generated and destroy the antioxidant system in cells.

Figure 3

Schematic diagram of Cd toxicity on molecule and cell in fish.