Expression and cell-specific and membrane-specific localization of NHE-3 in the human and guinea pig upper gastrointestinal tract
| Autor: | Hüseyin Bektas, Hasan Kulaksiz, Yalcin Cetin |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
DNA
Complementary Sodium-Hydrogen Exchangers Histology Brush border Duodenum Blotting Western Guinea Pigs Biology Basement Membrane Pathology and Forensic Medicine Sequence Homology Nucleic Acid medicine Gastric mucosa Animals Humans Tissue Distribution Intestinal Mucosa Cellular localization DNA Primers Epithelial polarity Base Sequence Reverse Transcriptase Polymerase Chain Reaction Sodium-Hydrogen Exchanger 3 Stomach Cell Membrane digestive oral and skin physiology Cell Polarity Membrane Proteins Cell Biology Apical membrane Membrane transport Immunohistochemistry Cell biology medicine.anatomical_structure Biochemistry Gastric Mucosa Sequence Analysis |
| Zdroj: | Cell and Tissue Research. 303:337-343 |
| ISSN: | 1432-0878 0302-766X |
| DOI: | 10.1007/s004410000329 |
| Popis: | Na+/H+ exchangers (NHEs) are vital transmembrane transport proteins mediating the electroneutral exchange of Na+ and H+ ions in mammalian cells. In the epithelium of the lower intestine, the isoform NHE-3 is apparently involved in Na+ absorption; however, its presence and cellular localization in the duodenum and particularly in the stomach remain largely unclear. Therefore, we studied the human and guinea pig stomach and duodenum for the expression, regional and mucosal distribution pattern, and membrane-specific localization of NHE-3. Reverse transcription/polymerase chain reaction analyses revealed strong expression of NHE-3 in the stomach and duodenum, where it was identified as a 85-kDa immunoreactive protein by Western blotting experiments. Whereas NHE-3 was localized to the basolateral membrane of surface mucous cells of the stomach, it was exclusively confined to the brush border membrane of epithelial cells in the duodenum. We conclude that the basolateral NHE-3 in the stomach protects the mucosa by secreting protons that diffuse into the mucous cells. In the duodenum, the localization of NHE-3 to the apical membrane of enterocytes suggests a resorptive function by directional Na+ transport. These findings indicate that NHE-3 may be involved in various segment-specific functions in the upper gastrointestinal tract. |
| Databáze: | OpenAIRE |
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