Hg^(2+)、Cd^(2+)对鱼类嗅觉的毒性及Ca^(2+)的解毒作用  

Study of structure function alterations of olfactory organ in Hg^(2+) 、Cd^(2+) poisoned Tilapia. Sp and the detoxifcation of Ca^( 2+)

作　　者：陈荣[1] 柴敏娟[1] 

机构地区：[1]厦门大学环境科学研究中心,厦门大学海洋学系福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2001年第3期726-734,共9页Journal of Xiamen University：Natural Science

基　　金：国家自然科学基金资助项目!( 39770 10 2 )

摘　　要：以罗非鱼为实验对象 ,采用电生理学和组织学方法系统研究了 4种不同浓度的 Hg2 +、Cd2 +污染液对鱼类嗅觉功能和嗅觉器官结构的损伤 ,以及 Ca2 +对 Hg2 +或 Cd2 +的解毒作用 ,结果表明 :1)Hg2 +、Cd2 +均可抑制罗非鱼嗅电图 ( electro- olfactogram,简称 EOG)反应 ,抑制效应随离子浓度的升高和污染时间的延长而增大 .Hg2 +的 IC50 值为 67.73μg/ L,Cd2 +为 33.91μg/ L,Cd2 +的抑制效应大于 Hg2 +.2 ) Ca2 ++Hg2 +、Ca2 ++Cd2 +混合液 (含 80 mg/ L Ca2 +)对 EOG的抑制作用均小于同浓度单一金属离子的抑制作用 ,表明 Ca2 +对 Hg2 +或 Cd2 +均有一定的解毒效应 ,其中 Ca2 +对 Hg2 +的解毒效应大于 Cd2 +.3)光镜研究显示 ,分别浸浴在 10、50 μg/ L Hg2 +或 Cd2 +4种污染液 15d后的罗非鱼嗅上皮均有不同程度的损伤 .在低浓度组 ,损伤主要是非感觉区粘液细胞出现增生现象 ;高浓度组的嗅上皮局部出现空泡化 ,嗅上皮边缘出现缺口并有细胞溢出 .在含 80 mg/ L Ca2 +的 10 μg/ L Hg2 +或Cd2 +混合组中 ,嗅上皮基本无损伤 ;在含同样浓度 Ca2 +的 50μg/ L Hg2 +或 Cd2 +混合组中 ,未见嗅上皮空泡化 。When these fish ( Tilapia. Sp) are exposed to four different kinds of Hg 2+ or Cd 2+ solutions, the structure function alterations of olfactory organ are systematically studied by electrophysiological and histological method, and the detoxifcation of Ca 2+ on Hg 2+ or Cd 2+ is also studied. The results are shown as follows: 1) Both of Hg 2+ and Cd 2+ are effective inhibitors on the EOG responses, and the inhibitions become stronger with the increasing of the ions concentration and prolonging of the polluted time. The IC 50 (concentration which inhibited respoonses by 50%) values of Hg 2+ and Cd 2+ are 67.73 μg/L and 33.90 μg/L, respectively. The inhibitory effect of Cd 2+ is stronger than that of Hg 2+ . 2) The inhibiting effects of the mixtures containing Ca 2+ (80 mg/L)+Hg 2+ or Ca 2+ (80 mg/L) + Cd 2+ weaker than that of single heavy metal ion with the same concentration, and the detoxifcation of Ca 2+ on Hg 2+ poisoned fish is much more pronounced than that of Cd 2+ . The results indicate that Ca 2+ has some detoxifcation on the Hg 2+ and Cd 2+ poisoned fish. 3) After 15 days exposure to four polluting solution of 10、50 μg/L Hg 2+ or Cd 2+ respectively, the olfactory epithelium of all polluted fish are observed different degree damage by light microscopy. In the low concentration groups, the main alteration is the hypertrophy of mucous cells in the non sensory region. In the high concentration groups, some vacuoles appear in the regional olfactory epithelium; some cells spill over the surface of olfactory epithelium from the region of dead sensory cells. When the olfactory epithelium of Tilapia. SP is exposed to the mixture containing 80 mg/L Ca 2+ and 10 μg/L Hg 2+ or Cd 2+ , no changes is observed by light microscopy. But mixture groups containing 80 mg/L Ca 2+ and 50 μg/L Hg 2+ or Cd 2+ , olfactory epithelium has cellular shrinkage and no vac

关 键 词：罗非鱼 嗅觉 毒性 解毒 汞离子 镉离子 钙离子 水体污染 

分 类 号：X52[环境科学与工程—环境工程] X174