溶解氧对团头鲂耐低氧新品系F5代的鳃组织形态及各组织酶活性的影响

Effects of oxygen on the gill tissue and enzyme activities of each tissue in a hypoxia-tolerant new strain F5 of Megalobrama amblycephala

中文关键词: 团头鲂  溶解氧  鳃组织  酶活性

英文关键词: Megalobrama amblycephala  Dissolved oxygen  Gill tissue  Enzyme activity

中文摘要:

      为研究不同浓度溶解氧(DO)对团头鲂(Megalobrama amblycephala)耐低氧新品系F5代鳃组织形态以及各组织酶活性的影响，本研究将团头鲂在低氧[DO为(1.7±0.2) mg/L]和高氧[DO为(19.3± 0.5) mg/L]条件下分别处理0、4和7 d，恢复常氧[DO为(7.8±0.3) mg/L] 7 d后，通过石蜡切片观察鳃组织的形态，并测定了鳃、肝胰腺、肠道、肌肉中过氧化氢酶(CAT)、琥珀酸脱氢酶(SDH)及乳酸脱氢酶(LDH)活性和丙二醛(MDA)含量。石蜡切片结果显示，随着低氧处理时间的延长，团头鲂新品系鳃丝的层间细胞团体积减小，鳃小片表面积增加，恢复常氧7 d后又有所恢复。高氧条件下，层间细胞团体积增大，鳃小片表面积减小，恢复常氧7 d后也会恢复。酶活性检测结果显示，在低氧和高氧2种条件下，随着处理时间的延长，CAT活性和MDA含量在各组织中的变化无明显规律，但均有显著差异(P<0.05)。低氧条件下，LDH活性显著增高，SDH活性显著降低(P<0.05)。高氧条件下，LDH活性显著降低，SDH活性显著增高(P<0.05)。本研究可为溶解氧对团头鲂的鳃组织以及各组织酶活性的影响提供基础资料，并为团头鲂新品系的养殖与选育奠定基础。

英文摘要:

      To study the effect of different dissolved oxygen (DO) concentrations on the gill morphology and enzyme activity of a hypoxia-tolerant new strain F5 of Megalobrama amblycephala, we placed the new strain in fish tanks with low oxygen [DO: (1.7±0.2) mg/L] and high oxygen [DO: (19.3±0.5) mg/L] concentrations for 0 d, 4 d, 7 d, and recovery [DO: (7.8±0.3) mg/L]. The morphology of the gill tissue was observed from paraffin sections and malondialdehyde (MDA) content, catalase (CAT), succinate dehydrogenase (SDH), and lactate dehydrogenase (LDH) activities in the gills, hepatopancreas, intestines, and muscle were determined. The results of the paraffin sections showed that with longer hypoxia time, the interlaminar cell mass of the branchial filaments of the new strain decreased, whereas the surface area of the branchial filaments increased and recovered after 7 days of constant oxygen. Under hyperoxic conditions, the substratum intercellular mass increased and the surface area of the branchial patches decreased. The results of the enzyme activity test showed that the changes of CAT activity and MDA content in different tissues had no obvious regularity with the extension of treatment time under both hypoxic and hyperoxic conditions; however, there were significant differences (P<0.05). LDH activity increased significantly and SDH activity decreased significantly under hypoxic conditions (P<0.05), whereas LDH activity decreased and SDH increased significantly under hyperoxic conditions (P<0.05). This study provided baseline data on the effect of DO on the gill tissue and enzyme activity of different tissues and laid the foundation for the breeding of new strains of M. amblycephala.