The effects of gastrectomy on experimental colonic cancer in the rat induced by 1, 2-Dimethyl-hydrazine (DMH) was studied. Ninetyfour animals were randomly separated into 5 groups : (1) sham operation with an injection of DMH, (2) gastrectomy Billroth I method (B-I) without an injection of DMH, (3) gastrectomy B-I with an injection of DMH, (4) gastrectomy Billroth II method (B-II) without an injection of DMH, (5) gastrectomy B-II with an injection of DMH.
Serum levels of gastrin in gastrectomized animals were significantly lower than in the controls and gastrectomy did not alter the level of pepsinogen I . The numder of colonic tumors per animal was significantly larger in gastrectomized animals than in the controls, and the sizes of the tumor were larger in gastrectomized animals. However, the incidence of colonic cancer did not differ in each group.
From the increasing number of colonic tumors associated with consequent hypogastrinemia after gastrectomy, it is possible that gastrin may exert a trophic effect on colonic mucosa.