Harayashiki Cyntia Ayumi Yokota, Reichelt-Brushett Amanda, Butcher Paul, Benkendorff Kirsten
Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia.
National Marine Science Centre, Southern Cross University, PO Box 4321, Coffs Harbour, NSW, 2450, Australia.
Ecotoxicology. 2018 Nov;27(9):1225-1236. doi: 10.1007/s10646-018-1975-8. Epub 2018 Sep 5.
There is a lack of information regarding the effects on biochemical markers in invertebrates diet-exposed to inorganic mercury. In the present study, juvenile black tiger prawn (Penaeus monodon) were fed with food dosed with mercuric chloride (low: 0.2 mg kg; medium: 0.77 mg kg; high: 1.41 mg kg; higher: 2.52 mg kg) and control (0.03 mg kg) over 12 days. At the end of exposure periods, ventral nerve cord, compound eyes and muscle were dissected for biochemical marker analyses (acetylcholinesterase - AChE; lipoperoxidation - LPO; glutathione S-transferase - GST; catalase - CAT). Prawn muscle showed an increase in total mercury concentration over time for low and high treatments, but did not show an accumulation in comparison to controls. AChE activity tended to decrease over time in all tissues. CAT activity increased over time in controls and lower dose treatments but was suppressed in the higher treatment relative to controls on day 12; indicating that inorganic mercury is impacting the normal stress response by reducing the capacity to degrade hydrogen peroxide. In contrast, no effect was observed in LPO and GST activity. A depuration treatment was performed and compared to medium treatment; only AChE and GST activities from muscle showed significant difference, with AChE activity from depuration treatment lower than medium treatment, while the opposite was observed in GST activity. Overall, the low mercury accumulation observed over 12 days of exposure may have limited the biochemical stress responses, which could also have limited the detection of differences in the depuration treatment relative to medium treatment.
关于无脊椎动物食用受无机汞污染的食物后对生化标志物的影响，目前缺乏相关信息。在本研究中，对幼年黑虎虾（斑节对虾）投喂添加了氯化汞的食物（低剂量：0.2毫克/千克；中剂量：0.77毫克/千克；高剂量：1.41毫克/千克；更高剂量：2.52毫克/千克），并设置对照组（0.03毫克/千克），持续投喂12天。在暴露期结束时，解剖腹神经索、复眼和肌肉进行生化标志物分析（乙酰胆碱酯酶 - AChE；脂质过氧化 - LPO；谷胱甘肽S - 转移酶 - GST；过氧化氢酶 - CAT）。低剂量和高剂量处理的对虾肌肉中总汞浓度随时间增加，但与对照组相比未显示出积累。所有组织中的AChE活性随时间有下降趋势。对照组和低剂量处理组中CAT活性随时间增加，但在第12天，高剂量处理组相对于对照组其活性受到抑制；这表明无机汞通过降低降解过氧化氢的能力影响正常应激反应。相比之下，未观察到LPO和GST活性有变化。进行了净化处理并与中剂量处理组进行比较；仅肌肉中的AChE和GST活性显示出显著差异，净化处理组的AChE活性低于中剂量处理组，而GST活性则相反。总体而言，暴露12天期间观察到的低汞积累可能限制了生化应激反应，这也可能限制了相对于中剂量处理组在净化处理中差异的检测。
