• 关键词：镉和锌  吸收途径  亚细胞组分  鳃  河南华溪蟹

• 基金项目：国家自然科学基金(No.31272319);高等学校博士学科点专项科研基金(博导类)(No.20111401110010);山西省特色学科重点项目(No.2011-SXDX-SWX-003)

• 李颖君
• 山西大学生命科学学院, 太原 030006

• 柴茜
• 山西大学生命科学学院, 太原 030006

• 井维鑫
• 山西大学生命科学学院, 太原 030006

• 王兰
• 山西大学生命科学学院, 太原 030006

• 摘要：采用火焰原子分光光度法检测了河南华溪蟹(Sinopotamon henanense)鳃中重金属镉、锌的含量,进而探讨了镉、锌两种金属在河南华溪蟹鳃组织中的吸收途径及亚细胞分布情况.实验首先运用Ca²⁺通道抑制剂三氯化镧(LaCl₃)和巯基抑制剂N-乙烷基顺丁烯二酰亚胺(NEM)对河南华溪蟹预处理4 h,然后再用不同浓度镉(50、100、500 μg · L^-1)、锌(100、1000 μg · L^-1)分别处理7 d.实验结果显示,LaCl₃仅抑制了鳃组织中镉的吸收,而NEM抑制了鳃组织中镉、锌的吸收.在亚细胞组分中,LaCl₃降低了镉在细胞碎片和细胞器中的分布,NEM减少了镉在热稳定蛋白及锌在热变性蛋白部分的分布;两种抑制剂均增加了锌在金属富含颗粒部分的分布.实验结果表明,在河南华溪蟹鳃组织的不同亚细胞组分中,镉、锌两种重金属的分布具有差异,推测LaCl₃和NEM均可调控镉的吸收,而NEM只调控锌的吸收.

• Abstract：This study investigated the uptake pathway and sub-cellular distribution of cadmium (Cd) and zinc (Zn) in the gills of freshwater crab Sinopotamon henanense using flame atomic absorption spectrophotometry for metal quantification. Crabs were treated with various concentrations of Cd (50, 100 and 500 μg · L^-1) or Zn (100 and 1000 μg · L^-1) for 7 days with pre-exposure to a calcium-channel blocker LaCl₃ and a thiol inhibitor N-ethyl maleimide (NEM) for 4 hours. Our results showed that in the gills the levels of accumulated Cd and Zn were reduced by the pre-treatment of thiol inhibitor N-ethyl maleimide (NEM); calcium-channel inhibitor LaCl₃ only blocked Cd uptake. The subcellular analysis showed that LaCl₃ inhibited the Cd accumulation in cellular debris and organelles. NEM lowered the Cd accumulation in heat-stable proteins and Zn accumulation in heat denatured proteins. Both inhibitors enhanced the Zn accumulation in metal-rich granules. In conclusion, our results indicate that the metals can accumulate in different sub-cellular components of the gills of the crab, and suggest that the uptake of Cd is mediated by both LaCl₃ and NEM, while the uptake of Zn is mediated by NEM.

• Key words：zinc and cadmium  uptake pathway  sub-cellular distribution  gills  Sinopotamon henanense

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