[Morphological findings and functional considerations on the structural adaptation of colonic grafts on the rat stomach].

Structural changes of colonic patches implanted in rat stomachs for periods of 2 to 12 months were evaluated by standard light and scanning electron microscopy. Colonic patches were sutured on the posterior wall of 116 white rats stomach body according to the following models: 1) mucosal surface to gastric lumen (60 rats); one third of the animals were given chronic doses of histamine subcutaneously; 2) peritoneal surface to gastric lumen (28 rats); 3) leiomuscular layers to gastric lumen by removing of the colonic mucosa (20 rats). Eight rats were used as controls. The colonic mucosa was shown to be highly resistant to acid secretions; only minimal surface erosions were found in animals with gastric hypersecretion following histamine stimulation. In contrast both the peritoneal surface and the colonic leiomuscular components were completely destroyed by contact with the acid juice. Both these structures were subsequently and completely colonised by the gastric mucosa.