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Cell Kinetic Study on Histogenesis of Barrett's Esophagus Using Rat Reflux Model

Background: To elucidate the histogenesis of Barrett's esophagus and esophageal adenocarcinoma, we designed a duodeno-gastric reflux model in which normal stomach function and normal nutritional status are retained. Methods: Male Wistar rats were used in the experiment. The esophago-gastric junction was side-to-side anastomosed to a loop of jejunum about 3 r cm distal to Treitz's ligament. The animals were not exposed to any known carcinogens during the experiment. Sequential morphological changes were studied for up to 50 weeks after surgery. Serial sections were made and stained with hematoxylin and eosin (H&E). In addition, immunohistochemical staining for bromodeoxyuridine (BrdU) was performed along with histochemical staining for mucins using paradoxical concanavalin A (ConA), galactose oxidase Schiff (GOS), and high-iron diamine-alcian blue (HID-AB). Results: Severe esophagitis with squamous cell hyperplasia was noted in all animals after surgery. At week 20 after surgery, glandular metaplastic cells positive for ConA first appeared within the basal cell layer of esophageal squamous cell epithelium, and then GOS-positive cells and HID-AB goblet cells appeared. This is a characteristic of the specialized columnar epithelium of Barrett's esophagus. We detected esophageal adenocarcinomas in 1 out of 8 subjects at week 40 and in 3 out of 8 subjects at week 50 after surgery. Conclusions: Reflux of duodenal contents causes specialized columnar epithelium of Barrett's esophagus and esophageal adenocarcinoma. As part of the sequence of events leading to the development of Barrett's esophagus, pyloric-foveolar metaplasia was observed followed by the appearance of intestinal goblet cells. The pyloric-foveolar metaplasia appears to be associated with chronic mucosal damage and regeneration. This multiplastic cell lineage is referred to as 'gut-regenerative cell lineage' (GRCL).