Abstract:Metabolic diseases, which are always characterized with abnormal lipid metabolism and severe fat deposition, have been commonly observed in farmed fish. However, the causes of the abnormal lipid metabolism in fish are complicated and difficult to be identified. In recent years, several studies have shown that environmental endocrine disrupting chemicals (EDCs), which are widely spread in the aquatic environment, not only have chronic toxic effects on fish development and reproduction, but also affect fish lipid metabolism and cause severe fat deposition, which would damage the quality and food safety of farmed fish. For the first time, this review systematically reviews the effects of EDCs on fish lipid metabolism. Persistent organic pollutants (POPs), heavy metals (Hg, Pb, Cd and Cu), environmental estrogens and artificially synthesized medicines (fibrates and antibiotics) are four major EDCs in water environment. In general, water or dietary exposure of these EDCs would disturb the biochemical activities and/or expressions of the enzyme proteins in the lipid metabolism pathways, including upregulating lipogenesis, inhibiting mitochondrial fatty acid β-oxidation, adipose tissue lipolysis and lipid transport cross tissues, and so on. The exposure of EDCs with high doses would also impair the functions of cellular organelles, such as mitochondria and peroxisome, which are important in the lipid metabolism. Recently, the disturbing effects of EDCs on some lipid metabolism-related nuclear receptors, such as peroxisome proliferators-activated receptors (PPARs) and sterol-regulatory element binding proteins (SREBPs), had also been found. However, it should be pointed out that among these EDCs, they also have specific mechanisms in affecting fish lipid metabolism and tissue deposition of fat. Even in the same EDC, different exposure method, duration and doses would also cause different effects in disturbing lipid metabolism in fish. In future research, more attentions should be paid on the endocrine disturbing effects of new environmental pollutants, combined effects of different EDCs, and the molecular mechanisms of EDCs effects. This review is helpful in studying EDCs in fish metabolism and also provides important theoretical supports for green and sustainable aquaculture development.
