Interactive effect of thermal and hypoxia on largemouth bass (Micropterus salmoides) gill and liver: Aggravation of oxidative stress, inhibition of immunity and promotion of cell apoptosis

Publication date: Available online 23 November 2019Source: Fish & Shellfish ImmunologyAuthor(s): Jun-Long Sun, Liu-Lan Zhao, Lei Liao, Xiao-Hong Tang, Can Cui, Qiao Liu, Kuo He, Ji-Deng Ma, Long Jin, Tao Yan, Jian Zhou, Song YangAbstractHigh temperatures and low oxygen in aquatic environments, such as intensive aquaculture or in natural watersheds, inevitably cause stress in fish. Fish are exposed to high temperatures during the summer, which exacerbates hypoxia. Hypoxia (1.2 ± 0.2 mg/L) under 20 °C (20HG) and 26 °C (26HG) was simulated to induce stress in largemouth bass (Micropterus salmoides). Related enzymes and genes involved in antioxidant, immune, and apoptotic responses were selected to explore the interactive effects of temperature and hypoxia on largemouth bass. The results showed that malondialdehyde (MDA) levels in plasma, gill, and liver increased in the 26 HG (p < 0.05). Liver superoxide dismutase (SOD) activity increased in the 26 HG. Peak SOD (SOD1, SOD2, SOD3a, and SOD3b), CAT, and GSH-Px mRNA levels in the gill and liver were observed at 12–24 h of stress. The levels of gill and liver total antioxidant capacity, catalase (CAT), glutathione peroxidase (GSH-Px) activities and other enzyme activities and genes in the 26 HG were higher than those in the 20 HG (p < 0.05). The gill and liver acid phosphatase and alkaline phosphatase activities increased with time in the 26 HG (p < 0.05), while gill and liver lysoz...
Source: Fish and Shellfish Immunology - Category: Biology Source Type: research