Cl- impermeability in cystic fibrosis (CF) tracheal epithelium derives from a deficiency in the β-adrenergic regulation of apical membrane Cl- channels. To test the possibility that cAMP-dependent kinase is the cause of this deficiency, we assayed this kinase in soluble fractions from cultured airway epithelial cells, including CF human tracheal epithelial cells. Varying levels of cAMP were used in these assays to derive both a V(max) and apparent dissociation constant (K(d)) for the enzymes in soluble extracts. The cAMP-dependent protein kinase from CF human tracheal epithelial cells has essentially the same V(max) and apparent K(d) as non-CF human, bovine, and dog tracheal epithelial cells. Thus, the total activity of the cAMP-dependent kinases and their overall responsiveness to cAMP are unchanged in CF.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Clinical Investigation|
|State||Published - 1987|
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