Expression and regulation of chloride channels in neonatal rat cardiomyocytes

✍ Scribed by Ben C. Tilly; Karel Bezstarosti; Wendy E.M. Boomaars; Christopher R. Marino; Jos M.J. Lamers; Hugo R.

• Book ID: 104672880
• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 614 KB
• Volume: 157
• Category: Article
• ISSN: 0300-8177
• DOI: 10.1007/bf00227891

✦ Synopsis

Using an 125I- efflux assay, we have studied the expression of various types of chloride channels in isolated neonatal rat cardiomyocytes. Three different classes of anion conductances were distinguished: (1) a Ca(2+)-sensitive Cl- conductance, triggered upon stimulation of the cells with endothelin-1 or Ca(2+)-ionophore; (2) a cAMP/protein kinase A-operated Cl- conductance, activated by addition of forskolin. This anion channel could be identified as the Cystic Fibrosis Transmembrane conductance Regulator (CFTR-CI- channel) by Western blotting as well as by its enhanced activity in cultures pretreated with the tyrosine kinase inhibitor genistein; (3) a distinct class of cell volume-regulated Cl- channels, potentiated in the presence of endothelin-1 or the phosphotyrosine phosphatase inhibitor pervanadate. The potential role of each class of Cl- channels in the generation and/or modulation of action potentials as well as in maintaining cell volume is discussed.