干露胁迫对脊尾白虾(Exopalaemon carinicauda)呼吸代谢相关酶的影响

Effects of Dry Exposure on the Respiratory Metabolism-Related Enzymes of Exopalaemon carinicauda

中文关键词: 脊尾白虾  干露  呼吸代谢酶  无氧代谢

英文关键词: Exopalaemon carinicauda  Dry exposure  Respiratory metabolism enzymes  Anaerobic metabolism

中文摘要:

      为了研究离水干露对脊尾白虾(Exopalaemon carinicauda)呼吸代谢能力的影响，以常温干露(22–24℃)、低温干露(4℃) 2个实验组和1个对照组进行脊尾白虾干露胁迫实验，于胁迫后60、90、120、180 min取组织，测定琥珀酸脱氢酶(SDH)、细胞色素氧化酶(CCO)、延胡索酸还原酶(FRD)、乳酸脱氢酶(LDH) 4种呼吸代谢酶活力和乳酸含量。结果显示，常温干露组肝胰腺、鳃、肌肉SDH和CCO活力随干露时间的延长而降低，且显著低于对照组(P<0.05)；FRD、LDH活力和肌肉乳酸含量随胁迫时间的延长呈先升高后降低趋势，且显著高于对照组(P<0.05)。低温干露组在胁迫60 min时，各组织呼吸代谢酶活力和肌肉乳酸含量与对照组无显著差异(P>0.05)，之后的变化趋势和常温干露组相同。常温干露组和低温干露组中肝胰腺和鳃SDH/FRD比值的变化幅度大于肌肉。研究表明，脊尾白虾通过提高无氧代谢来应对干露胁迫；低温干露下的脊尾白虾在胁迫早期可以维持有氧呼吸，肝胰腺和鳃比肌肉对干露胁迫更加敏感。

英文摘要:

      The objective of the present research was to investigate the effects of dry exposure on respiratory metabolism in different tissues of Exopalaemon carinicauda. In the trial, E. carinicauda were divided into two experimental groups, namely normal temperature (22-24℃) group and low temperature (4℃) group. Meanwhile, shrimp cultured in seawater were used as the control group. Activities of respiratory metabolism enzymes and content of lactate were measured under dry exposure challenges at 60 min, 90 min, 120 min and 180 min. The investigated enzymes included succinate dehydrogenase (SDH), cytochrome oxidase (CCO), fumarate reductase (FRD) and lactate dehydrogenase (LDH). SDH and CCO are the key enzymes of aerobic metabolism in animals, whereas FRD and LDH are the key enzymes of anaerobic metabolism in animals. In addition, the content of lactate is an indicator of anaerobic metabolism. The results showed that the activities of SDH and CCO in hepatopancreas, gill, and muscle in the normal temperature group decreased significantly than those in the control (P<0.05) with the processes of dry exposure. Activities of FRD, LDH and content of lactate in muscle increased initially and then decreased gradually. And the levels were significantly higher than those in the control (P<0.05). Activities of respiratory metabolism enzymes and content of lactate in low temperature group had no significant difference compared to those in the control group at 60 min. After that, the trends of the enzyme levels in the low temperature group were as similar as the normal temperature group. The changes of enzyme activities were tissue dependent. Activities of respiratory metabolic enzymes in hepatopancreas and gill were higher than those in muscle. The results suggested that anaerobic metabolism increased after dry exposure. By contrast, E. carinicauda can maintain the aerobic metabolism during the early stage of low temperature dry exposure. Furthermore, the hepatopancreas and gill might be more sensitive to dry exposure, whereas reduced temperature could increase the survival rate of E. carinicauda.