急性低氧胁迫和复氧对梭鲈鳃组织氧化应激和细胞凋亡的影响OA

[Background]In recent years,factors such as extreme climate,high-density aquaculture and water eutrophication have led to increased fluctuations in dissolved oxygen concentration in water,consequently hyp-oxia in aquatic animals has become more frequent.Pike perch(Sander lucioperca)is an economically import-ant fish species and highly sensitive to hypoxic conditions.[Objective]This study aims to investigate the ef-fects of hypoxic stress on the gill tissue structure,antioxidant capacity and gene expression of S.lucioperca.[Methods]Acute hypoxic stress(0,6,48 h)and reoxygenation(6 h)experiments were conducted to analyze the structural changes,oxidative stress status and gene expression differences of gill tissues in S.lucioperca.[Results]Hypoxic stress resulted in significant damage to the structure of S.lucioperca gill lamellae.It also significantly increased(P<0.05)the activities of antioxidant enzymes(SOD,CAT,GSH-Px),and the mRNA ex-pression of pro-apoptotic genes(Bax,Caspase3),while significantly decreasing(P<0.05)in the mRNA expres-sion of anti-apoptotic genes(Bcl-2).The mRNA expression of Egln-2,a gene encoding prolyl hydroxylase,first decreased and then increased,while the mRNA expression of Hif-1a,a key factor of the hypoxia signalling pathway,first increased and then decreased.After reoxygenation,the gill tissue structure and related indexes re-covered but did not fully reach the level of the control group.[Conclusion]Hypoxic stress significantly altered physiological and biochemical indicators as well as gill lamellae morphology in S.lucioperca,while short-term reoxygenation(6 h)markedly alleviated hypoxic stress responses.[Significance]The study could provide baseline data for further elucidation of the regulatory mechanism of hypoxic stress in S.lucioperca.