Mechanism for gastric carcinogenesis by H.pylori infection

我们研究了Hp感染在新生BALB/c小鼠胸腺切除后发生各种肿瘤损害的机制。结果：1.幽门螺杆菌感染BALB/c小鼠后，持续感染的发生率较低，且几乎未见胃粘膜炎症。相反，当幽门螺杆菌感染出生后3天切除胸腺的BALB/c小鼠时，所有小鼠都出现了持续感染，这与胃粘膜的显著炎症有关。在这些小鼠中，感染后3个月胃窦粘膜出现肠化生。4.在这些去胸腺的小鼠中，10%的小鼠在感染后6个月出现胃腺瘤。但感染后1年仍未发现胃癌。在这些胸腺切除的小鼠中，淋巴滤泡的发育被观察到…感染后2个月以上复发，其中70%发展为胃MALT淋巴瘤。在这些小鼠中，大约30%的小鼠在感染后1年观察到胃类癌的形成。血清胃泌素浓度为1450×96pg/ml，显著高于未感染组(116×10pg/ml)和未感染组(765×56pg/ml)(P&lt；0.01)。此外，在感染的小鼠中，用特定的胃泌素受体拮抗剂AG041R治疗，没有观察到类癌的形成。胃MALT淋巴瘤、胃腺瘤和胃类癌没有同时发生。幽门螺杆菌数量和血清胃泌素水平的排序为类癌、腺瘤和MALT淋巴瘤，胃酸分泌物的排序为MALT淋巴瘤、腺瘤和类癌。宿主因素，如酸分泌和激素分泌的能力，以及免疫反应，可能是决定各种疾病表型发生的重要因素。较少

We examined mechanisms for development of various neoplastic lesions by H.pylori infection in neonatal thymectomized BALB/c mice. Thymectomy was performed 3 days after birth, and H.pylori was infected orally at 2 months after thymectomy, and following results were obtained :1. When we infected H.pylori to BALB/c mice, persistent infection did not occur so often, and moreover, we hardly observed mucosal inflammation of the stomach.2. In contrast, when H.pylori was infected to BALB/c mice thymectomized 3 days after birth, persistent infection developed in all the mice, which was associated with prominent inflammation of the gastric mucosa.3. In these mice, intestinal metaplasia developed in the antral mucosa at 3 months after the infection.4.In these thymectomized mice, 10% of them developed gastric adenoma at 6 months after the infection. However, gastric cancer could not be observed even 1 year after the infection.5. In these thymectomized mice, development of lympho-follicles was obse … More rved 2 months after the infection, and moreover, 70% of them developed gastric MALT lymphoma.6. In these mice, gastric carcinoid formation was observed at 1 year after the infection in about 30% of all the animals. Serum gastrin concentrations of these mice was 1450 * 96 pg/ml, whchi was significantly higher than that of non-infected mice (116 * 10 pg/ml) and that of the infected mice without carcinoid formation (765 * 56 pg/ ml) (P < 0.01). Moreover, in the infected mice who were treated with a specific gastrin receptor antagonist, AG041R, no carcinoid formation was observed.7. Gastric MALT lymphoma, gastric adenoma, and gastric carcinoid did not develop concomittantly. Rank orders of the number of H.pylori and serum gastrin level was carcinoid > adenoma > MALT lymphoma, whereas that of gastric acid secretion was MALT lymphoma > adenoma > carcinoid.8. Host factors such as capacity of acid secretion and hormone secretion, and immunological responses may be important for deciding the occurence of various disease phenotypes. Less