抗虫耐除草剂玉米对大鼠的亚慢性毒性研究

Sub-chronic toxicity test of genetically modified insect-and herbicide-resistant corn in rats

目的:研究大鼠在90 d内经口重复喂饲含抗虫基因cry1Ab和cry3Bb、耐除草剂基因cp4epsps、高维生素基因ZmHPT和ZmTMT的玉米引起的毒性效应。方法:140只6周龄的Wistar大鼠,雌雄各半,按照不同饲料随机分为7组:基础饲料对照组,对照玉米低、中、高剂量组,转基因玉米低、中、高剂量组。分别喂饲含相应玉米的饲料90 d,观察体质量、进食量、血液生化指标、脏器系数及病理学检查。结果:各组大鼠试验周期内生长正常,部分转基因玉米组大鼠和对照玉米组大鼠体质量、进食、血液生化指标、脏器系数与基础饲料对照组大鼠比较,差异具有统计学意义(P<0.05),部分转基因玉米组大鼠体质量、进食、血液生化指标、脏器系数与对照玉米组大鼠比较,差异具有统计学意义(P<0.05),但是均无生物学意义。主要脏器组织病理学检查未发现明显异常。结论:在本实验条件下,未发现该转基因玉米对大鼠有亚慢性毒性作用。

OBJECTIVE:The study investigated toxic effects of sub-chronic oral exposures for 90 days in rats to genetically modified(GM)corn with insect-resistant gene cry1Ab and cry3Bb,herbicide-resistant gene cp4epsps,high vitamin gene ZmHPT and ZmTMT.METHODS:6-week-old Westar rats,half males and half females,were randomly divided into 7 groups with 20 per group according to weight:basic feed control group,non-GM corn groups(low-,medium-and high-doses),GM corn experimental groups(low-,medium-and high-doses).Rats were fed the different corns for 90 consecutive days.Then,they were observed for changes in body weight,food intake,blood biochemical indicators,organ coefficients and pathological features.RESULTS:Rats in each dose group grew normally during the test cycle.The body weight,food intake,blood biochemical indexes,organ coefficients of some GM corn and non-GM corn groups were significantly different from those in the control animals(P<0.05).In addition,the differences were also significantly different between the GM corn compared with the non-GM corn groups(P<0.05).However,no significant abnormalities were found in the pathology examinations of some main organ tissues.CONCLUSION:The experimental results show that sub-chronic exposure to the genetically modified corns did not lead to obvious pathological changes in rats.