镉胁迫对蛆症异蚤蝇幼虫体内脂质过氧化物含量及抗氧化酶活性的影响

Effects of Cadmium Stress on the Lipid Peroxide Content and Antioxidant Enzyme Activity in Megaselia scalaris Larva

为研究蛆症异蚤蝇Megaselia scalaris(Loew)幼虫在重金属镉胁迫下体内脂质过氧化物含量及抗氧化酶活力的变化,将蛆症异蚤蝇幼虫孵化后分别提供常规饲料、含7.5μg/g、15μg/g、30μg/g和60μg/g重金属镉(Cd^2+)的饲料。每天分别取样,至蛆症异蚤蝇羽化。蛆症异蚤蝇幼虫采用直接研磨法获得酶液。分别采用试剂盒测定脂质过氧化物丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-PX)活力,数据采用多重比较进行统计学分析。结果显示,随着Cd2+胁迫浓度的升高和取食时间的增加,蛆症异蚤蝇幼虫体内MDA含量整体增加,具有浓度依赖效应和时间依赖效应关系;SOD和CAT活性呈低浓度(7.5μg/g,15μg/g,30μg/g)促进,高浓度(60μg/g)抑制的规律性变化;GSH-PX活性在各处理浓度下均呈下降趋势。本研究表明在镉胁迫条件下能够引起蛆症异蚤蝇幼虫体内脂质过氧化损伤,并且能够引起体内抗氧化酶活力规律变化。

To study the changes of lipid peroxide content and antioxidant enzyme activity of larva Megaselia scalaris(Loew)under the stress of heavy metal cadmium,newly hatched larvae of M.scalaris were provided with routine feed as control and the feed containing 7.5μg/g,15μg/g,30μg/g and 60μg/g of heavy metal cadmium(Cd^2+).Samples were taken every day until the emergence of adults.The enzyme solution was obtained by direct grinding method.The lipid peroxide malondialdehyde(MDA)content,superoxide dismutase(SOD),catalase(CAT)and glutathione peroxidase(GSH-PX)activity were determined with the kit,and the data were statistically analyzed by multiple comparisons.As the concentration of Cd2+increased and the feeding time prolonged,the content of MDA in the body of larvae increased as a whole,showing a concentration and time dependent effect.SOD and CAT activity was promoted by low concentration(7.5μg/g,15μg/g,30μg/g)and inhibited by high concentration(60μg/g).The activity of GSH-PX decreased at all treatment concentrations.This study showed that cadmium stress can cause lipid peroxidation damage in the body of the larvae of M.scalaris,and can cause changes in the activity of antioxidant enzymes in the body.