Compensatory postresectional hyperplasia and starvation atrophy in small bowel: dissociation from endogenous gastrin levels.

Because exogenous gastrin has been implicated as a tropic hormone for mucosal cells of the intestinal tract and as a regulator of mucosal growth, we studied the effects on the gut of endogenous 23-fold variations of serum gastrin produced by various gastric operations. These were pyloroplasty, vagotomy and pyloroplasty, antrectomy, and fundectomy. After jejunal resection, RNA content, DNA content, incorporation of [3H]thymidine into DNA, crypt depth, and villus height in midgut and ileum were independent of gastrin levels. Loss of RNA and DNA during starvation was not prevented by high endogenous concentrations of serum gastrin, and DNA specific activity was not affected. Tropic effects distal to the duodenum produced by exogenous gastrin and pentagastrin may be results of supranormal levels.