铬在中华稻蝗（Oxya chinensis）体内的累积及对抗氧化系统的影响

昆虫体内的重金属主要是通过消化途径实现代谢过程的。本文中以不同浓度六价铬（Cr6＋）溶液（0、7.5、15、30mg·L^-1）培育的小麦对中华稻蝗（Oxya chinensis）从4龄若虫开始进行慢性染毒,待其发育到成虫时分别测定虫体、粪便、小麦叶片内的Cr含量以及成虫体内超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPx）和总抗氧化能力（T-Aoc）。结果显示,生长于0、7.5、15、30mg·L^-1Cr6＋溶液中的小麦,其叶片中Cr浓度分别为5.77、6.85、9.88、18.33μg·g^-1。随着Cr6＋浓度的增加,虫体内和粪便中Cr的累积量也逐渐增大,在30mg·L^-1时达到最大值。中华稻蝗体内SOD活力随着处理浓度的增加,变化不明显,未达到显著水平。而CAT、GPx活力和T-Aoc随着处理浓度的增加,呈先升高后降低的趋势,在7.5mg·L^-1时达到最大值。本文结果表明,中华稻蝗体内的Cr含量随着染毒浓度的增加而增大,是对环境中重金属Cr污染的一种间接反应。通过测定中华稻蝗体内的Cr含量,可以对环境中Cr污染进行评估;同时,中华稻蝗抗氧化酶系统在机体防御过氧化物损伤方面起着重要作用。

Accumulation of Chromium in Oxya chinensis and Its Effects on the Antioxidant System

Heavy metals in insects are mainly achieved by the ways of metabolism through digestion. In the present study,Oxya chinensis,from the fourth-instar nymphs to adults,were fed on wheat seedlings cultured in Cr6＋ solutions of different contents（0,7.5,15 mg·L^-1 and 30 mg·L^-1）. The Cr contents were determined in the wheat seedlings,the body and droppings of O. chinensis,and the superoxide dismutase（SOD）,catalase（CAT）,glutathione peroxidase（GPx） activity and total antioxidant capacity（T-Aoc） were measured in O. chinensis. The Cr contents in wheat seedlings were 5.77,6.85,9.88 μg·g^-1 and 18.33 μg·g^-1,respectively,when they were cultured in different Cr6＋ contents（0,7.5,15 and 30 mg·L^-1）. The Cr contents increased gradually in the O. chinensis body and droppings with the increasing of Cr6＋ content,and the Cr contents reached maximum at 30 mg·L^-1 Cr6＋ treatment group. With the increasing of Cr6＋ contents,the activity of SOD remained almost unchanged,however,the T-Aoc and the activity of CAT,GPx firstly increased and then decreased,and the activities reached the maximum in 7.5 mg·L^-1. In conclusion,the Cr content in the body of O. chinensis is the indirect reflect for the heavy metal pollution in the environment. Therefore,through the determination of Cr contents in O. chinensis,the heavy metal pollution in environment can be evaluated. The antioxidant system in O. chinensis plays important functions for the organism against peroxidation.