Some Properties of Sodium and Chloride Channels in Respiratory Epithelia of CF- and Non-CF-Patients
Thus far patch clamp studies on single channel properties of respiratory epithelia have mainly focussed on Cl- channels (9, 10, 13, 15, 16, 21, 23). This has been so for two reasons: 1. The disturbance in Cl- conductance was the first transport defect to be discovered in CF epithelia (19, 22) and 2. In single channel studies on respiratory epithelia Cl- channels are found more frequently and identified and studied more easily than the low conductance, slowly switching Na+ channels. On the other hand, however, it has been known for almost ten years that sodium transport is increased in CF epithelia (12) and this alteration of sodium transport may even be more relevant as a pathogenetic factor since it may affect the transepithelial fluid balance in the bronchi more than the inability to secrete chloride (see contribution by Boucher and collaborators to this symposium). In the present paper, therefore, we shall mainly discuss our recent studies on properties of Na+ channels and shall, at the end, only briefly mention some of our recent experiments concerning the regulation of Cl- channels.
KeywordsCystic Fibrosis Single Channel Chloride Channel Respiratory Epithelium Single Channel Conductance
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