Gill oxidative damage caused by acute ammonia stress was reduced through the HIF-1α/NF-κb signaling pathway in golden pompano (Trachinotus ovatus)

• DOI: 10.1016/j.ecoenv.2021.112504
• Publication Date: 2021-07-12T16:48:07Z
• Authors: Ming-Jian Liu; Hua-Yang Guo; Bo Liu; Ke-Cheng Zhu; Liang Guo; Bao-Suo Liu; Nan Zhang; Jing-Wen Yang; Shi-Gui Jiang; Dian-Chang Zhang
• Keywords: Fish Proteins; Gills; Inflammatory response; 04 agricultural and veterinary sciences; Animal Feed; Environmental pollution; Antioxidants; Histological changes; Biochemical parameters; Environmental sciences; Oxidative Stress; Fish; TD172-193.5; Oxidative stress; Ammonia; Dietary Supplements; Animals; 0401 agriculture, forestry, and fisheries; GE1-350; Signal Transduction

This study aimed to investigate the intoxication mechanism of golden pompano (Trachinotus ovatus) exposed to high ammonia levels and the effects on the immune and antioxidant mechanisms of gills. Juvenile golden pompano was exposed to ammonia (total ammonia: 26.9 mg/L) to induce 96 h of ammonia stress, and a 96 h recovery experiment was performed after poisoning. Then, we evaluated hematological parameters, the histological structure and the expression of related genes. In this experiment, continuous exposure to high levels of ammonia led to a significant increase in plasma alkaline phosphatase (ALP), acid phosphatase (ACP) and lactate dehydrogenase (LDH) levels (P < 0.05), and the levels of triiodothyronine (T3) and tetraiodothyronine (T4) were significantly reduced (P < 0.05). Moreover, the expression of antioxidant genes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and inflammatory cytokines such as tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) increased (P < 0.05). These results indicate that ammonia activates the active osmotic regulatory mechanism of fish gills and participates in defense and immune responses. However, with prolonged exposure to ammonia, the balance of the defense system is disrupted, leading to oxidative damage and inflammation of the gill tissue. This research not only helps elucidate the intoxication mechanism of golden pompano by ammonia at the molecular level but also provides a theoretical basis for further research on detoxification mechanisms.