Increased incidence of neoplasms in rats exposed to low levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin
Increased incidence of neoplasms in rats exposed to low levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin
复制标题
暴露于低水平 2,3,7,8-四氯二苯并-对二恶英的大鼠肿瘤发病率增加
DOI：
10.1016/0045-6535(77)90073-x
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发表时间：
1977
期刊：
影响因子：
8.8
通讯作者：
James R. Allen
中科院分区：
文献类型：
--
作者：
J. Miller;J. Lalich;James R. Allen
材料和方法将重约60 g的雄性Sprague-Dawley大鼠（Sprague-Dawley，麦迪逊，威斯康星州，美国）分成10个相等的组（每组10只动物）。将动物饲养在2个笼子里，并喂食地面食物（Purina Rat Chow，Ralston-Purina Co.，圣路易斯，密苏里州美国）两周。经过这段时间的适应后，动物被置于含有以下浓度之一的TCDD的饮食中：1，5，50，500万亿分之一（ppt; 10 -12克TCDD/克食物），1，5，50，500或1000十亿分之一（ppb; 10 -9克TCDD/克食物）。此外，一组维持实验前饮食作为对照。实验饲料按5 kg批次制备如下。将适量的TCDD悬浮于0.5 ml丙酮中，并溶解于100 ml玉米油中。将玉米油加入约1 kg磨碎的食物中并充分混合。然后将该预混物与剩余的食物混合以产生5 kg。将饲料储存在-5 ℃以防止腐败。将每组的两只动物隔离，并监测其摄食量2周。第一个月每周记录三次所有动物的体重，此后每两周记录一次。在实验第65周之前，未以任何其他方式操作动物，此时对所有存活动物进行剖腹术。在剖腹手术时，从观察到的任何肿瘤中获得活组织检查。动物维持饮食78周。此时，将实验动物置于对照饲料中。在95周时，处死所有存活动物。
MATERIALS AND METHODS Male Sprague-Dawley rats (Sprague-Dawley, Madison, Wisconsin USA) weighing approximately 60 g were divided into lO equal groups (lO animals per group). The animals were housed 2 to a cage and fed ground chow (Purina Rat Chow, Ralston-Purina Co., St. Louis, Missouri USA) for two weeks. After this period of acclimation, the animals were placed on a diet containing one of the following concentrations of TCDD: l, 5, 50, 500 parts per trillion (ppt; lO-12 g TCDD/g food), l, 5, 50, 500 or lO00 parts per billion (ppb; IO-9 g TCDD/g food). In addition, one group was maintained on the pre-experimental diet to serve as controls. The experimental diets were prepared in 5 kg batches as follows. The appropriate quantity of TCDD was suspended in 0.5 ml of acetone and dissolved in lO0 ml of corn oil. The corn oil was added to approximately 1 kg of ground chow and mixed thoroughly. This premix was then mixed with the remaining chow to yield 5 kg. The diets were stored at-5 C to prevent spoilage. Two animals from each group were isolated and their food intake monitored for 2 weeks. Weights were recorded for all of the animals three times weekly for the first month and every two weeks thereafter. The animals were not manipulated in any other way until the 65th week of the experiment when laparotomies were performed on all of the surviving animals. At the time of l aparotomy biopsies were obtained from any tumors observed. The animals were maintained on the diets for 78 weeks. At that time the experimental animals were placed on the control diet. At 95 weeks all surviving animals were sacrificed.