Yamuna A, Bhavan P Saravana, Geraldine P
Department of Animal Science, Bharathidasan University, Tiruchirappalli - 620 024, India.
J Environ Biol. 2012 Jan;33(1):133-7.
Healthy juveniles of M. malcolmsoniiwere exposed to 24.1 microg l(-1) of mercury (96 hr LC50: 145 microg l(-1) Hg) for a period of 21 days. The hepatopancreas and gills of the prawns were sampled on 8th, 15th and 22nd day of exposure. Accumulation and elimination of Hg, activity of glutathione S-transferase (GST), content of glutathione (GSH) and metallothionein (MT) level were studied. Mercury accumulation was found to be higher in the hepatopancreas (88.60 microg g(-1)) and lower in the gills (67.8 microg g(-1)). However, Hg elimination was found to be faster in the gills (62%) and slower in the hepatopancreas (58%). Therefore, the rate of Hg elimination did not match the rate of its uptake. The activity of GST was found to be higher in tissues of test prawns (5.94-9.13 nmol mg(-1) protein min(-1)) on all sampling days when compared with controls (3.454.23 nmol mg(-1) protein min(-1)). Similarly, the content of GSH was found to be higher in tissues of test prawns (0.80-1.43 micromol g(-1) protein) on all sampling days when compared with controls (0.55-1.00 micromol g(-1) protein). These results indicate the formation of glutathione conjugate in test prawns to eliminate Hg. The induction of MT level was also found to be higher in tissues of test prawns (57.50-75.76 nmol g(-1) protein) on all sampling days when compared with control (20.24-45.22 nmol g(-1) protein). This indicates the fact that sequestration of Hg has occurred for its easy elimination. Thus, induction of GST-GSH and MT ensured protection and adaptation of test prawns to thrive in Hg contaminated environment.
将健康的马氏沼虾幼体暴露于24.1微克/升的汞中（96小时半数致死浓度：145微克/升汞），持续21天。在暴露的第8天、第15天和第22天对虾的肝胰腺和鳃进行采样。研究了汞的积累和消除、谷胱甘肽S-转移酶（GST）的活性、谷胱甘肽（GSH）的含量以及金属硫蛋白（MT）水平。发现肝胰腺中的汞积累量较高（88.60微克/克），鳃中的汞积累量较低（67.8微克/克）。然而，发现鳃中汞的消除速度较快（62%），肝胰腺中汞的消除速度较慢（58%）。因此，汞的消除速率与其摄取速率不匹配。与对照组（3.45 - 4.23纳摩尔/毫克蛋白质·分钟）相比，在所有采样日，试验虾组织中的GST活性均较高（5.94 - 9.13纳摩尔/毫克蛋白质·分钟）。同样，与对照组（0.55 - 1.00微摩尔/克蛋白质）相比，在所有采样日，试验虾组织中的GSH含量均较高（0.80 - 1.43微摩尔/克蛋白质）。这些结果表明试验虾中形成了谷胱甘肽共轭物以消除汞。与对照组（20.24 - 45.22纳摩尔/克蛋白质）相比，在所有采样日，试验虾组织中的MT水平诱导也较高（57.50 - 75.76纳摩尔/克蛋白质）。这表明已经发生了汞的螯合以便于消除。因此，GST - GSH和MT的诱导确保了试验虾在汞污染环境中生存的保护和适应。
