Importance of the fecal stream on the induction of colon tumors by azoxymethane in rats.
Importance of the fecal stream on the induction of colon tumors by azoxymethane in rats.
复制标题
粪便流对氧化偶氮甲烷诱导大鼠结肠肿瘤的重要性。
作者：
R. Campbell;D. V. Singh;N. Nigro
本文研究了粪流对氧化偶氮甲烷诱发大鼠小肠癌的影响。在50只Sprague-Dawley大鼠的盲肠远端约2 cm处进行结肠造口术，以产生20 cm的无功能大肠段;另外50只动物保持完整。将这些组中的每一组平均分配，并喂食正常饮食或含有2%考来烯胺的饮食。所有动物均皮下注射氧化偶氮甲烷。7个月后处死所有大鼠。结肠造口的动物在去功能化的肠中产生的肿瘤明显少于相同肠段中的完整动物。考来烯胺似乎增加了完整动物大肠中的肿瘤产量，但对去功能化肠中的肿瘤数量没有影响。此外，两种饮食方案的完整动物在肠的远端20 cm处产生了更多数量的大肿瘤。结果表明，粪便流改变了大鼠大肠中氧化偶氮甲烷的致癌活性。此外，致癌物质似乎可以通过粪便流以外的途径到达其靶组织。
The effect of the fecal stream on intestinal carcinogenesis with azoxymethane was studied in male rats. Colostomies were performed approximately 2 cm distal to the cecum in 50 Sprague-Dawley rats to produce a 20-cm segment of nonfunctional large bowel; an additional 50 animals were left intact. Each of these groups was divided equally and was fed a normal diet or a diet containing 2% cholestyramine by weight. All animals were given azoxymethan s.c. At the end of 7 months all rats were sacrificed. The animals with colostomies developed significantly fewer tumors in the defunctionalized bowel than did intact animals in the same bowel segment. Cholestyramine appeared to increase the tumor yield in the large bowel of the intact animals but had no effect on the number of tumors in the defunctionalized bowel. Further, the intact animals on both dietary regimens developed a greater number of large tumors in the distal 20 cm of bowel. The results show that the fecal stream alters the carcinogenic activity of azoxymethane in the large bowel of the rat. It also appears that the carcinogen can reach its target tissue by a route other than the fecal stream.