铜砷单一污染对蚯蚓体腔细胞的影响

Effects of Mono-contamination of Cu and As on Coelomocytes of Earthworm Eisenia foetida

蚯蚓是土壤污染的重要指示者。本实验的主要目标就是要研究重金属对蚯蚓以及参与防御反应的体腔细胞的影响。人工土壤用4个浓度的铜与砷染毒,然后把成熟的赤子爱胜蚓在其中分别放置2、7与14d。结果表明,随着金属离子浓度的增大与时间的增加,蚯蚓的生长率不断降低。中性红保持时间与重金属的剂量有一定的联系,浓度越高,中性红保持时间越短,随着时间的增加甚至会减少为0。黏附细胞吞噬活性与细胞吞饮作用也受到重金属的影响而减弱,这也说明重金属对蚯蚓中与免疫相关的体腔细胞影响较大。或许,免疫功能的破坏导致蚯蚓在重金属污染的土壤中生存活力较差。

Based on the Artificial Soil Test（OECD-guideline No.207 ）with earthworm as the indicator, since earthworms are sensitive bio-indicators of soil pollution, the effects of heavy metals on earthworms（Eiseniafoetida）and their coelomocytes involved in the defensive reactions were studied at individual and cell level. Earthworms were exposed to a range of increasing soil copper and arsenic concentrations in a mesocosm experiment for 2, 7 and 14 days. The results showed that, with the increasing concentrations of the heavy metals and the exposure time, the growth of Eiseniafuetida was reduced gradually. Under normal conditions, the average neutral red retention was 94.3 rain. After inducement, the assay demonstrated a clear dose-response, with the increase of heavy metals concentration, the retention time accordingly decreased and even reduced to zero. NRR closely related to the metal concentration and exposure time. In addition, significant impairment of pinocytosis and plastic adherence were revealed for coelomocytes, which in turn clarified the great impact of heavy metals on the coelomocytes related to immunity. Perbaps the impairment of immune functions contributed to the poor survival of Eiseniafoetida in heavily polluted soils with heavy metals.