Schreiber, R. and Koenig, J. and Sun, J. and Markovich, D. and Kunzelmann, Karl (2003) Effects of purinergic stimulation, CFTR and osmotic stress on amiloride-sensitive Na+ transport in epithelia and Xenopus oocytes. JOURNAL OF MEMBRANE BIOLOGY, 192 (2). pp. 101-110. ISSN 0022-2631
Full text not available from this repository.Abstract
Both stimulation of purinergic receptors by ATP and activation of the cystic fibrosis transmembrane conductance regulator (CFTR) inhibit amiloride-sensitive Na+ transport and activate Cl-secretion. These changes in ion transport may well affect cell volume. We therefore examined whether cell shrinkage or cell swelling do affect amiloride-sensitive Na+ transport in epithelial tissues or Xenopus oocytes and whether osmotic stress interferes with regulation of Na+ transport by ATP or CFTR. Stimulation of purinergic receptors by ATP/UTP or activation of CFTR by IBMX and forskolin inhibited amiloride-sensitive transport in mouse trachea and colon, respectively, by a mechanism that was Cl- dependent. When exposed to a hypertonic but not hypotonic bath solution, amiloride-sensitive Na+ transport was inhibited in mouse trachea and colon, independent of the extracellular Cl- concentration. Both inhibition of Na+ transport by hypertonic bath solution and ATP were additive. When coexpressed in Xenopus oocytes, activation of CFTR by IBMX and forskolin inhibited the epithelial Na+ channel (ENaC) in a Cl(-)dependent fashion. However, both hypertonic and hypotonic bath solutions showed only minor effects on amiloride-sensitive conductance, independent of the bath Cl- concentration. Moreover, CFTR-induced inhibition of ENaC could be detected in chocytes even after exposure to hypertonic or bypotonic bath solutions. We conclude that amiloride-sensitive Na+ absorption in mouse airways and colon is inhibited by cell shrinkage by a mechanism that does not interfere with purinergic and CFTR-mediated inhibition of ENaC.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | TRANSMEMBRANE CONDUCTANCE REGULATOR; CYSTIC-FIBROSIS AIRWAYS; HYPERTONIC SALINE; ION-TRANSPORT; EXTRACELLULAR NUCLEOTIDES; MEDIATED INHIBITION; CYTOSOLIC NA+; DUCT CELLS; WILD-TYPE; ABSORPTION; CFTR; EnaC; Xenopus oocytes; mouse trachea; cystic fibrosis; cell swelling; osmotic stress; UTP; ATP; purinergic receptors; epithelial transport |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Physiologie > Prof. Dr. Karl Kunzelmann |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 17 Aug 2021 14:05 |
| Last Modified: | 17 Aug 2021 14:05 |
| URI: | https://pred.uni-regensburg.de/id/eprint/39197 |
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