饲料铜含量对亚硝酸盐胁迫下斑节对虾血细胞的影响

研究了饲料铜离子含量对亚硝酸盐胁迫下斑节对虾（Penaeus monodon）血细胞参数的影响。向斑节对虾投喂不同铜离子添加量（0，10，25，40，55和110 mg/kg）的饲料8周后，进行24 h 的20 mg/L亚硝酸氮胁迫，取样测定对虾的血细胞总数（THC）、血细胞活性氧（ROS）含量和血细胞凋亡率。结果显示，经亚硝酸盐胁迫后，25-55 mg/kg饲料组对虾能保持较高的THC，以及较低血细胞ROS含量和凋亡率；110 mg/kg饲料组对虾的THC最低，血细胞ROS含量和凋亡率均最高。这些结果表明饲料中添加25-55 mg/kg的铜离子能有效降低亚硝酸盐胁迫对血细胞造成的氧化损害，但过量添加（110 mg/kg）反而对血细胞造成更为严重的损害。

Effect of dietary copper levels on haemocytes of Penaeus monodon exposed to nitrite

Effects of dietary copper levels on haemocyte parameters were investigated in nitrite-exposed tiger shrimp Penaeus monodon. After shrimp fed the diets supplemented with different dose of Cu2+ (0, 10, 25, 40, 55 and 110 mg/kg) for 8 weeks, a 24 h exposure of 20 mg/L nitrite was conducted, and then total haemocyte count (THC), reactive oxygen species (ROS) production and apoptotic haemocyte ratio were determined. Results showed that after exposure to nitrite, shrimp fed diets supplemented Cu with 25-55 mg/kg had the higher THC, and lower ROS production and apoptotic ratio. Shrimp fed diets supplemented Cu with 110 mg/kg had the lowest THC, and highest ROS production and apoptotic ratio. These results indicate that dietary supplemental Cu with 25-55 mg/kg could protect the haemocytes against the oxidative damage induced by nitrite. However, excess dietary supplemental Cu (110 mg/kg) would exacerbate the damage on haemocytes.