Immunolocalization of Transforming Growth Factor-α and Epidermal Growth Factor Receptor in the Rat Gastroduodenal Area

The maintenance of gastrointestinal epitheliumintegrity requires a fine balance between proliferationand differentiation as well as protection againstgastric acid secretion. Transforming growthfactor-α (TGF-α) regulates these functions bybinding to epidermal growth factor receptor (EGF-R).This study was designed to identify the localization ofTGF-α and EGF-R in the rat gastroduodenal region. In the stomach, the surface and gastric pitcells showed staining for TGF-α antibodies in thecytoplasm and basolateral and apical membranes.TGF-α and EGF-R were observed in the supranuclearregion of the cells lining the gland. In the duodenum,the enterocytes coexpressed both TGF-α and EGF-Rin the supranuclear area. The EGF-R was also observed inthe apical membrane. Brunner's glands were positive for both TGF-α and EGF-R antibodies. Ourresults demonstrate the coexpression of TGF-α andEGF-R in the rat gastroduodenal area, which suggests afunctional role for them in the establishment and maintenance of the epithelialrenewal.