| Autor: |
C, Rückes-Nilges, U, Weber, C, Popp, A, Fryen, T, Klimek, H, Glanz, H, Lindemann, G, Münker, W, Clauss, W M, Weber |
| Jazyk: |
němčina |
| Rok vydání: |
1999 |
| Předmět: |
|
| Zdroj: |
HNO. 47(3) |
| ISSN: |
0017-6192 |
| Popis: |
Cystic fibrosis (CF) is the most commonly inherited disease in Caucasians and is caused by a mutation in the gene encoding a membrane transport protein. This cystic fibrosis transmembrane conductance regulator (CFTR) is thought to be an apical Cl- channel activated by intracellular cAMP. Most recent findings suggest that CFTR is more than a pure Cl- channel and might be involved in the regulation of other transport systems. In the present study we show that CFTR as a Cl- channel plays only a minor role in primary cultured human nasal epithelium derived from non-CF and CF patients. These findings are especially of interest for non-CF human nasal epithelia in which CFTR is correctly inserted. In both tissues Cl- secretion is negligible as compared with Na+ absorption. We confirm and expand our previous observations that Na+ absorption in human nasal epithelium is the dominant ion transport process and that Cl- secretion is detectable in both CF and non-CF tissue. Moreover, we show that cAMP and ATP were not able to stimulate any silent Cl- channels in CF or non-CF human nasal epithelial cells. We further give evidence that in human nasal CF and non-CF epithelium Na+ absorption is mediated by epithelial Na+ channels (ENaC) that are either different from those of other epithelia or which exhibit altered regulation. These differences between Na+ channels of human nasal epithelium and "classical" epithelial Na+ channels include lack of activation by the intracellular second messenger cAMP and the steroid hormone aldosterone. We show further that human nasal Na+ channels are inhibited by Cl- channel blockers and exhibit a different pharmacology towards common Na+ channel blockers. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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