Demonstration of a pH gradient in the gastric gland of the acid-secreting guinea pig mucosa
| Autor: | Thanh Hoa Nguyen, Peter Scheid, Sören Schreiber, Manuela Stüben |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
medicine.medical_specialty
Physiology Guinea Pigs Biology Membrane Potentials Guinea pig Gastric Acid Physiology (medical) Gastric glands Internal medicine medicine Gastric mucosa Animals Enterochromaffin-like cell Hepatology Stomach digestive oral and skin physiology Gastroenterology Biological Transport Epithelial Cells Hydrogen-Ion Concentration Molecular biology Mucus Electrophysiology Foveolar cell Endocrinology medicine.anatomical_structure Gastric Mucosa Gastric acid Microelectrodes |
| Zdroj: | American journal of physiology. Gastrointestinal and liver physiology. 279(3) |
| ISSN: | 0193-1857 |
| Popis: | The gastric mucosa is covered by a continuous layer of mucus. Although important for understanding the mechanism of this protective function, only scarce information exists about the pH inside the gastric gland and its outlet. pH in the lumen of the gastric glands, in the outlet of gastric crypts, and in the adjacent cells was measured in the isolated acid-secreting mucosa of the guinea pig. Ultrafine double-barreled pH microelectrodes were advanced at high acceleration rates through the gastric mucus and the tissue to ensure precise intracellular and gland lumen pH measurements. A pH gradient was found to exist along the gastric gland, where the pH is 3.0 at parietal cells, i.e., in the deepest regions, and increases to 4.6 at the crypt outlet. Intracellular pH (pHi) of epithelial cells bordering a crypt outlet, and of neck cells bordering a gland, was acidic, averaging 6.0 and 6.5, respectively. pHi of deep cells bordering a gland was nearly neutral, averaging 7.1, and the secreting parietal cells were characterized by a slightly alkaline pHi of 7.5. This gland pH gradient is in general agreement with a model that we recently proposed for proton transport in the gastric mucus, in which protons secreted by the parietal cells are buffered to and transported with the simultaneously secreted mucus toward the gastric lumen, where they are liberated from the degraded mucus. |
| Databáze: | OpenAIRE |
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