Acquisition of a gastric or duodenal phenotype on heterotropic transplantation of esophagus and bladder tissues in F344 rats.

Cell differentiation is very important but not well understood. In the present study the ability of various tissues to newly-differentiate when transplanted into the fundus or the duodenum in rats was tested. Pieces of esophagus, bladder, diaphragm and trachea from 8-week-old male F344 rats were transplanted into the gastric fundus or duodenum of females and examined after 3 or 6 months. While the diaphragm was not recognizable as a muscle layer in either the stomach or the duodenum, the esophagus and trachea persisted, the latter with the presence of cartilage. Esophagus grafts transplanted into the glandular stomach and duodenum, newly-differentiated into gastric and duodenal mucosa, respectively. Goblet cells with alcian-blue positive mucin appeared in bladder tissue implanted into the duodenum. Six months after the operation, their numbers had increased and cytoplasm alkaline phosphatase (ALP) positivity was noted. Gastrointestinal and also bladder stem cells may thus have multipotential ability for differentiation and may be able to newly-differentiate when transplanted into different environments in the gastrointestinal tract.