Calman K C
Gut. 1974 Jul;15(7):552-4. doi: 10.1136/gut.15.7.552.
It is a well known clinical observation that small bowel tumours are rarer than tumours of the stomach or colon. The fluidity and relative sterility of small bowel contents, and rapid transit time and of the relative sterility of the small bowel itself have been suggested as possible factors contributing to this relatively low incidence. A further mechanism, that of a local immune response against malignant cells, has also been suggested and this investigation is the subject of this paper. A transplantable tumour (Gardner lymphosarcoma) was injected either into the stomach or small bowel of CBA mice, and the incidence of subsequent tumour growth was studied when the immune status of the host mouse was altered. Normal mice, mice ;deprived' by thymectomy and irradiation (T-cell-deficient mice), and ;reconstituted mice' (prepared as the ;deprived' animals but given a thymus graft) were used. The results showed that in normal and reconstituted mice more tumours arise in the stomach than in the small bowel but that in deprived mice the incidence of tumours was the same in both sites. This could be taken to suggest that local immune responses can suppress the development of tumours of the small bowel.
小肠肿瘤比胃或结肠肿瘤少见，这是一个广为人知的临床观察结果。小肠内容物的流动性和相对无菌性、快速的转运时间以及小肠本身的相对无菌性，被认为是导致这种相对低发病率的可能因素。另一种机制，即针对恶性细胞的局部免疫反应，也被提出，本文的研究主题就是这个。将一种可移植肿瘤（加德纳淋巴肉瘤）注射到CBA小鼠的胃或小肠中，当宿主小鼠的免疫状态改变时，研究随后肿瘤生长的发生率。使用了正常小鼠、通过胸腺切除和照射“剥夺”免疫功能的小鼠（T细胞缺陷小鼠）以及“重建小鼠”（制备方式与“剥夺”免疫功能的动物相同，但给予胸腺移植）。结果表明，在正常和重建小鼠中，胃中出现的肿瘤比小肠中多，但在“剥夺”免疫功能的小鼠中，两个部位的肿瘤发生率相同。这可以表明局部免疫反应能够抑制小肠肿瘤的发展。
