Cd^(2+)、Pb^(2+)、Hg^(2+)对泥蚶鳃及消化腺显微结构和超微结构的影响

Effect of Cd^(2+),Pb^(2+),Hg^(2+) on the Microstructure and Ultrastructure of Gill and Hepatopancreas in Tegillaraca Granosa

研究了9μg/L暴毒浓度的镉(Cd2+)、铅(Pb2+)和1.08μg/L暴毒浓度的汞(Hg2+)对泥蚶鳃和消化腺组织显微结构和超微结构的影响。实验处理时间为28d。3种重金属胁迫下鳃组织显微结构观察显示鳃丝排列混乱,血细胞堆积现象严重;超微结构观察发现,Cd2+和Hg2+胁迫下鳃细胞发生细胞核皱缩,有大量的线粒体和溶酶体。Pb2+攻毒组的鳃细胞中聚集大量的嗜锇性物质。3种重金属胁迫下消化腺组织显微结构显示消化腺细胞破碎,完整度变差;从超微结构来看,在Cd2+和Pb2+的胁迫下,消化腺细胞中出现嗜锇性物质;另外在Pb2+胁迫下,消化腺细胞中有溶酶体;然而在Hg2+胁迫下,泥蚶消化腺细胞受到的影响不明显。本研究推测在重金属胁迫下,泥蚶可能会通过溶酶体和重金属形成不溶性颗粒,从而将重金属隔离进行解毒作用;大量产生的线粒体可能对重金属引起的氧化胁迫进行呼吸补偿反应。

The aim of this study is to investigate that the long-time stress under the low concentration of Cd^2＋,Pb^2＋and Hg^2＋influence the microstructure and ultrastructure of gill and hepatopancreas in Tegillaraca granosa.The experiment exposed to concentration of Cd^2＋,Pb^2＋（9μg/L）and the concentration of Hg^2＋（1.08μg/L）,lasted for 28 days.The results of three metals influencing the microstructure of gill cells were as follows：under the toxic influence of Cd^2＋,Pb^2＋,Hg^2＋,the gill filament arranged chaos,in which stored lots of haemocytes.The ultrastructure showed that the nuclei of gill shriveled,and a number of lysosomes and mitochondrion gathered under Cd^2＋and Hg^2＋stress.Besides,a number of granular osmiophilic material gathered in the gill under the exposure of Pb^2＋.Under the toxic effects of these three heavy metals,the microstructure of hepatopancreas cells disrupted and their integrity weakened.The main ultrastructure influence of Cd^2＋and Pb^2＋on hepatopancreas cells was the exist of granular osmiophilic material.In addition,there were lysosomes in the hepatopancreas cells which were exposed at Pb^2＋.Under Hg^2＋exposure,there was no significant effect.So It comes to the conclusions that under heavy metal stress,Tegillarca granosa maybe isolate heavy metal by combined with lysosomes to detoxify and gathered a number of mitochondrion for respiratory compensation which caused oxidative stress by three heavy metal to respond.