土壤中亚致死剂量毒死蜱对蚯蚓抗氧化防御系统酶活性的影响

EFFECT OF CHLORPYRIFOS OF A SUBLETHAL DOSE ON ENZYME ACTIVITY OF THE ANTIOXIDANT DEFENSE SYSTEM OF EARTHWORMS

以赤子爱胜蚓(Eisenia fetida)为供试生物,研究了暴露于含有亚致死剂量毒死蜱的人工土壤中8周时间内蚯蚓超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性的变化。结果表明,毒死蜱对蚯蚓SOD、CAT、GSH-Px酶活性具有显著抑制。蚯蚓抗氧化防御系统酶对毒死蜱毒性具有一定的指示作用。除蚯蚓的LC50、产卵率、卵孵化率等常用的蚯蚓生态毒理学指标外,蚯蚓的SOD、CAT、GSH-Px抗氧化酶活性与实验农药的毒性效应具有相关性,但各指标在对毒性的响应敏感性上存在差异,其中,SOD、GSH-Px最为敏感,而CAT最不敏感。因此,在生态毒性诊断时,应选择不同指标作为一套指标体系相互补充,以增强污染诊断的灵敏性及长期诊断。

Earthworms （Eisenia fetida） as subject in the test are exposed to chlorpyrifos of a sub-lethal dose for 8 weeks in artificial soil．Effects of the exposure on SOD, CAT, and GSH-Px activities in earthworms were observed. Results show that the compound suppressed the activities significantly. So the enzymes of the anti-oxidizing defense system of earthworms can be cited as indicators of chlorpyrifos toxicity. Besides the commonly used ecological toxicity indexes, such as LC50, oviposition rate and hatching rate, the activities of the antioxidases, were closely related to the toxic effect of the pesticide. However, the enzymes varied in sensitivity to the chemical． SOD and GSH-Px were more sensitive than CAT．Therefore, in diagnosing ecological toxicity, it is advisable to have different indices form a mutually supplementary indicator system to improve the sensitivity and efficiency of pollution identification and long term diagnosis．