Long-term hypoxia and reoxygenation induced oxidative stress lead to immunosuppression and apoptosis in golden pompano (Trachinotus blochii)

The fluctuations of dissolved oxygen (DO) often lead to hypoxia in aquaculture, which has a huge adverse impact on fish. This study mainly investigated the effects long-term oxidative stress, immune response, and cell apoptosis liver golden pompano ( Trachinotus blochii ), is not tolerant hypoxia. So we conducted 14 day low stress experiment with DO 3.0 ± 0.2 mg/L, then restore normal levels continue reoxygenation experiment. Results showed that led significant changes structure. During reoxygenation, expression related genes SOD1 , SOD2 GSH-Px CAT ) antioxidant enzymes (CAT MDA) were increased. Liver lysozyme activity relative pro-inflammatory factors interleukin IL)-1β significantly increased, but IL-34 was down-regulated during IL-12β increased reoxygenation. anti-inflammatory factor IL -11 decreased duringreoxygenation. toll like receptors TLRs -7, -8, -9 increases after decreases indicating both affect response. In addition, TUNEL-positive signals bcl2/bax ratio decreased, caspases-3 -8 up-regulated hypoxia, caspases-9 summary, can cause induce inflammatory reactions, inhibit processes, activate apoptosis, damage pompano, may be irreversible.