Chemical carcinogenesis in transposed intestinal segments.
Chemical carcinogenesis in transposed intestinal segments.
复制标题
转位肠段的化学致癌作用。
作者：
A. Gennaro;R. Villanueva;Y. Sukonthaman;V. Vathanophas;G. Rosemond
设计了一种研究模型来帮助评估小肠和结肠粘膜对潜在肠道致癌物的相对敏感性，并报道了该模型对氧化偶氮甲烷的应用。对 Sprague-Dawley 大鼠进行肠转位。在一组中，小肠段被转移到升结肠和降结肠，而在另一组中，结肠段被转移到中小肠水平。每周即时通讯术后几周开始注射氧化偶氮甲烷。通常，在 14 次注射后（尽管有时更早），一些大鼠死亡或出现肠道肿瘤的临床证据。这份初步报告是基于从这些动物和一些对照组动物的标本中获得的结果。
十八只进行结肠转位并接受氧化偶氮甲烷治疗的大鼠在转位部分发生了腺癌。 17只接受小肠转位并接受致癌物质的老鼠中，没有一只在转位的小肠中出现癌症；然而，每个人都患有一种或多种结肠癌。接受致癌物质但未进行手术的对照动物患上了结肠癌。接受致癌物质的对照组和手术组的动物均出现了位于十二指肠空肠区域的小肠肿瘤。有肠道转位但没有致癌物质的对照动物没有患上癌症。
这些早期发现表明，结肠粘膜，无论其在肠道中的位置如何，都容易受到致癌物氧化偶氮甲烷的影响，但小肠粘膜则不然。该实验与临床状态并不平行，但可能有助于理解癌症的生物学。
A research model has been devised to assist in an assessment of the relative susceptibility of small bowel and colonic mucosa to potential intestinal carcinogens, and an application of this model to azoxymethane is reported. Intestinal transpositions were performed on Sprague-Dawley rats. In one group, segments of small intestine were transposed to the ascending and descending colon and, in another group, colon segments were transposed to the level of the mide small bowel. Weekly i.m. injections of azoxymethane were started several weeks after operation. Usually, after 14 injections (although sometimes earlier) some of the rats died or presented clinical evidence of intestinal tumors. This preliminary report is based on findings obtained from specimens in these animals and in a few animals from the control groups.
Eighteen rats that had a colon transposition and that received azoxymethane developed adenocarcinoma in the transposed segment. None of the 17 rats that had a small bowel transposition and that received the carcinogen developed cancer in the transposed small intestine; however, each had one or more colon cancers. Control animals that received the carcinogen, but which had no operation, developed colon cancer. The animals in both control and operated groups that received the carcinogen developed small intestinal tumors that were localized in the duodenojejunal region. Control animals that had intestinal transpositions but no carcinogen did not develop cancer.
These early findings suggest that colon mucosa, regardless of its location in the intestinal tract, is susceptible to the carcinogen azoxymethane but that mucosa of the small intestine is not. The experiment does not parallel the clinical state but may prove helpful in understanding the biology of cancer.