Effect of waterborne zinc exposure on metal accumulation, enzymatic activities and histology of Synechogobius hasta

The present study was conducted to determine the metal accumulation, antioxidant enzymatic response, hepatic intermediary metabolism and histological changes in Synechogobius hasta exposed to 0.35 (control), 9.7 and 19.2 mg/L Zn, respectively, on the 0, 4th, 8th and 12th day. Waterborne Zn exposure significantly reduced hepatosomatic index, hepatic lipid contents and fatty liver occurrence rate, increased Zn, Fe and Mn contents and reduced the contents of Cu and Ca in liver, and increased muscle Zn content. Waterborne Zn exposure also significantly influenced enzymatic activities involved in antioxidant responses (superoxide dismutase, catalase, glutathione-S-transferase, malondialdehyde) in liver and spleen, and changed hepatic intermediary enzymatic activities (succinate dehydrogenase, malic dehydrogenase, lactate dehydrogenase, lipoprotein lipase, hepatic lipase), impaired the histological structure of the gill and spleen, and reduced vacuolated hepatocytes. Thus, our study demonstrated for the first time that waterborne Zn exposure could reduce fatty liver syndrome in S. hasta.

► Our study investigated enzymatic and histological alterations in S. hasta exposed to Zn. ► Our study provided critical information for the aquatic environmental risk assessment of Zn. ► Our study demonstrated for the first time that Zn could reduce fatty liver syndrome in S. hasta.