Modulation of L-type calcium channels by sodium ions

C. William Balke, W. Gil Wier

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


It is universally believed that the removal of external sodium ions is without effect on calcium current. We now report that in enzymatically isolated guinea pig ventricular cells, the replacement of external sodium ions with certain other cations causes a 3- to 6-fold increase in peak L-type calcium current. The increase in current is reversibly blocked by L-type calcium-channel antagonists, not mediated by changes in internal calcium, and is inhibited by intracellular S'-adenylyl intidodiphosphate, a nonhydrolyzable ATP analogue. The effects of sodium removal (and isoproterenol) were almost completely blocked by intracellular application of a speific (peptide) inhibitor of cAMP-dependent protein kinase. These experiments demonstrate a previously unknown effect of sodium ions to modulate calcium-channel phosphorylation via cAMP-dependent protein kinase.

Original languageEnglish
Pages (from-to)4417-4421
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number10
StatePublished - 1992


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