Abstract
The tetrodotoxin-sensitive sodium ion (Na+) channel is opened by cellular depolarization and favors the passage of Na+ over other ions. Activation of the β-adrenergic receptor or protein kinase A in rat heart cells transformed this Na+ channel into one that is promiscuous with respect to ion selectivity, permitting calcium ions (Ca2+) to permeate as readily as Na+. Similarly, nanomolar concentrations of cardiotonic steroids such as ouabain and digoxin switched the ion selectivity of the NA+ channel to this state of promiscuous permeability called slip-mode conductance. Slip-mode conductance o the Na+ channel can contribute significantly to local and global cardiac Ca2+ signaling and may be a general signaling mechanism in excitable cells.
Original language | English (US) |
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Pages (from-to) | 1027-1033 |
Number of pages | 7 |
Journal | Science |
Volume | 279 |
Issue number | 5353 |
DOIs | |
State | Published - Feb 13 1998 |
Externally published | Yes |
ASJC Scopus subject areas
- Medicine(all)
- General