重金属离子Cd2+对泥蚶鳃及肝脏细胞显微和超微结构的影响

研究了镉(Cd)的各个不同暴毒浓度(5,15,45,90μg/L)对泥蚶鳃和肝脏组织显微结构的影响,及高浓度暴毒情况下对泥蚶鳃和肝脏组织超微结构的影响。实验处理时间为96 h。结果发现,随着暴毒浓度的升高,鳃丝内腔隙肿胀,内有血细胞堆积,最后鳃丝出现断裂融合,其上的呼吸上皮细胞脱落,超微结构发现鳃上皮细胞中出现黑色嗜锇性物质,且次级溶酶体和线粒体数量都增加,最后细胞内出现空泡现象;Cd对肝脏显微结构的影响不大,仅出现了黄色沉积物,超微结构表明,肝细胞内亦出现了嗜锇性物质,次级溶酶体亦大量增加,这些现象与鳃丝内出现的情况一致,且肝细胞核还出现变形皱缩,甚至产生空泡,细胞出现了不可逆的损伤。最为敏感的线粒体和内质网没有出现损伤现象,研究推测可能是由于机体内Cd诱导产生的抗氧化活性酶作用的结果。

Effects of cadmium on the microstructure and ultrastructure of gill and hepatopancreas in Tegillarca granosa

The aim of this paper is to investigate the toxic influence of cadmium on the histopathological alterations of gill and hepatic cells in Tegillarca granosa exposed to various concentrations of cadmium(5 μg/L,15 μg/L,45 μg/L,90 μg/L).The experiment lasted for 96 hours.The results are as follows: as the metal concentration rose,the gill cavity swelled,in which stored lots of haemocytes;finally the gill broke and dissolved,where the epithelia cells dropped;the findings of ultrastructure showed that there was granular osmiophilic material in gill epithelia cells,moreover,the number of secondary lysosome and mitochondrion increased,and the cells became vacuolated.The influnce of cadmium on the microstructure of hepatic cells was not obvious,only turning up some yellow sediment.However,its ultrastructure results indicated that the granular osmiophilic material was also present,and the secondary lysosome increased as well,consistent with the cases in gill;Furthermore,the nucleus of hepatic cells deformed and shrank,even showed vacuoles,suggesting the cells were irreversibly damaged.But the two most sensitive organelle,mitochondrion and endoplasmic reticulum,were normal,so we infer that the results may be caused by antioxidant enzymes,which were induced by cadmium.