重金属镉对参环毛蚓表皮结构的损伤

目的：探讨不同浓度镉离子胁迫下,对参环毛蚓表皮结构的影响.方法：采用不同浓度镉离子胁迫参环毛蚓染毒、HE组织切片染色、光学显微镜,下观察其体表结构损伤的变化.结果：随着镉离子浓度的增加和染毒时间的增长,参环毛蚓的环带附近有充血肿胀、溃疡病变.在光学显微镜下,在低浓度组时,皮肤的超微结构却发生了明显的改变,皮肤角质层明显增厚,而在高浓度组时,表皮层发生溃疡,其皮肤的防御体系受到损坏,体表的角质层变薄.结论：重金属镉对参环毛蚓表皮结构具有明显的损伤,且随着浓度的增加和染毒时间的增长,这种损伤更加明显,反映了参环毛蚓对该重金属的防御性反应.

The role of cadmium in damage of epithelial structure in Pheretima aspergillum

Objective：To study the effects of different concentrations of cadmium ions on the epithelial structure of Pheretima aspergillum （ PA ）. Methods ： PAs were contaminated with different concentrations of cadmium ions. The damage of PA epithelial structure was then studied under light microscope using HE-stained tissue sections. Results： Along with increasing concentration of cadmium ion and duration of contamination, congestion, swelling and ulceration were noted in proximity of the PA clitellum. Under light microscope, the changes in ultrastructure of epithelium, including thickening of cuticle, was conspicuous even with low-dose contamination of cadmium. High-dose contamination of cadmium was found to be associated with ulcerated and thinned cuticle, suggesting presence of damage to the PA epithelial structure. Conclnsion： The heavy metal cadmium ions may cause substantial damage to PA epithelial structure. Such damage may be more significant along with higher dose and longer duration of contamination, reflecting a range of PA defensive responses to heavy metals.