转Cry1Ab-ma基因玉米对大鼠的亚慢性毒性研究

Subchronic Toxicity Test of Genetically Modified Corn with Cry1Ab-ma Gene in Rats

目的:研究转Cry1Ab-ma基因玉米对大鼠的亚慢性毒性。方法:初断乳Wistar大鼠140只,随机分为7组:转基因玉米高中低3个剂量组(60%、30%、15%)、亲本玉米高中低3个剂量组(60%、30%、15%)以及1个常规基础饲料对照组,每组20只,雌雄各半。动物2只1笼喂养,自由进食饮水,连续观察90 d。每周称量饲料量及大鼠体重,在试验中、末期采集大鼠尿液和血液进行尿常规、血常规和血生化分析。实验末期称重脏器并计算脏器体重比,最后对大鼠脏器进行病理组织学检查。实验末期称重脏器并计算脏器体重比,最后对大鼠脏器进行病理组织学检查。结果:90 d的实验期内,各组大鼠均未发现中毒死亡情况。转基因玉米组个别评价指标虽与亲本玉米对照组或常规基础饲料对照组存在统计学差异,但指标水平在文献报道正常范围和历史对照范围内,且均未发现有生物学意义的改变。各受检脏器未见与受试物相关的病理改变。结论:现有实验结果不能证实转Cry1Ab-ma基因玉米对大鼠有亚慢性毒性作用。

Objective To study the subchronic toxicity of genetically modified corn with Cry1Ab-ma gene in rats.Method A total of 140 first weaned Wistar rats were randomly divided into seven groups including high,medium and low doses of genetically modified corn groups(60%,30%,15%).High,medium and low doses of parental corn groups(60%,30%,15%)and a routine basal diet control group.Each group with 20 rats and half male and half female,two animals were fed in one cage,and they were free to eat and drink for 90 days of continuous observation.Food intake and body weight of each group were recorded every week.Blood and urine were collected at the middle and end of the experiment to determine hematology,blood biochemical index and routine urine index.At the end of the experiment,the organs were weighed,the organ/weight ratio was calculated,and the organs were analyzed histopathology.Result During the 90 day test period,no rat in each group died due to poisoning.Although only a few indicators of the genetically modified corn group were statistically different from the parental corn control group or the routine basal diet control group,the indicator levels were within the normal range that reported in the literature and the historical control range,and no biologically significant changes were found.There were no pathological changes related to the test substance in the examined organs.Conclusion The existing test results cannot confirm that genetically modified corn with Cry1Ab-ma gene has subchronic toxicity to rats.