| Autor: |
D I, Cook, A, Dinudom, P, Komwatana, J A, Young |
| Rok vydání: |
1998 |
| Předmět: |
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| Zdroj: |
European journal of morphology. |
| ISSN: |
0924-3860 |
| Popis: |
The duct cells of the mandibular glands of mice (and many other mammalian salivary glands) absorb NaCl from an isotonic, Na+-rich primary saliva, formed by the gland's secretory endpieces, utilising an amiloride-sensitive Na+ channel in the apical (luminal) domain of the plasma membranes. The present study focuses on the mechanisms whereby the apical membrane Na+ conductance is controlled so that the rate of Na+ influx from lumen to cytosol via the Na+ channels is matched to the rate of Na+ extrusion from cytosol to interstitium via the basolateral Na+-K+-ATPase (so called homocellular regulation or epithelial cross-talk). Our results show that the apical membrane Na+ conductance is not controlled by a sensor of extracellular (luminal) Na+, as has been previously believed, but by sensors of cytosolic Na+ and Cl- which down-regulate the Na+ channels when the cytosolic concentration of either ion increases. These effects of cytosolic Na+ and Cl- are mediated, respectively, by G proteins of the Gi and Go subclasses. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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