Constitutive Phosphodiesterase Activity Restricts Spontaneous Beating Rate of Cardiac Pacemaker Cells by Suppressing Local Ca2+Releases
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چکیده
منابع مشابه
Constitutive phosphodiesterase activity restricts spontaneous beating rate of cardiac pacemaker cells by suppressing local Ca2+ releases.
Spontaneous beating of rabbit sinoatrial node cells (SANCs) is controlled by cAMP-mediated, protein kinase A-dependent local subsarcolemmal ryanodine receptor Ca(2+) releases (LCRs). LCRs activated an inward Na(+)/Ca(2+) exchange current that increases the terminal diastolic depolarization rate and, therefore, the spontaneous SANC beating rate. Basal cAMP in SANCs is elevated, suggesting that c...
متن کاملConstitutive Phosphodiesterase Activity Restricts Spontaneous Beating Rate of Cardiac Pacemaker Cells by Suppressing Local Ca Releases
Spontaneous beating of rabbit sinoatrial node cells (SANCs) is controlled by cAMP-mediated, protein kinase A–dependent local subsarcolemmal ryanodine receptor Ca releases (LCRs). LCRs activated an inward Na /Ca exchange current that increases the terminal diastolic depolarization rate and, therefore, the spontaneous SANC beating rate. Basal cAMP in SANCs is elevated, suggesting that cAMP degrad...
متن کاملHigh Basal Protein Kinase A–Dependent Phosphorylation Drives Rhythmic Internal Ca Store Oscillations and Spontaneous Beating of Cardiac Pacemaker Cells
Local, rhythmic, subsarcolemmal Ca releases (LCRs) from the sarcoplasmic reticulum (SR) during diastolic depolarization in sinoatrial nodal cells (SANC) occur even in the basal state and activate an inward Na -Ca exchanger current that affects spontaneous beating. Why SANC can generate spontaneous LCRs under basal conditions, whereas ventricular cells cannot, has not previously been explained. ...
متن کاملHigh basal protein kinase A-dependent phosphorylation drives rhythmic internal Ca2+ store oscillations and spontaneous beating of cardiac pacemaker cells.
Local, rhythmic, subsarcolemmal Ca2+ releases (LCRs) from the sarcoplasmic reticulum (SR) during diastolic depolarization in sinoatrial nodal cells (SANC) occur even in the basal state and activate an inward Na(+)-Ca2+ exchanger current that affects spontaneous beating. Why SANC can generate spontaneous LCRs under basal conditions, whereas ventricular cells cannot, has not previously been expla...
متن کاملSarcoplasmic reticulum Ca2+ pumping kinetics regulates timing of local Ca2+ releases and spontaneous beating rate of rabbit sinoatrial node pacemaker cells.
RATIONALE Sinoatrial node cells (SANCs) generate local, subsarcolemmal Ca(2+) releases (LCRs) from sarcoplasmic reticulum (SR) during late diastolic depolarization. LCRs activate an inward Na(+)-Ca(2+) exchange current (I(NCX)), which accelerates diastolic depolarization rate, prompting the next action potential (AP). The LCR period, ie, a delay between AP-induced Ca(2+) transient and LCR appea...
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ژورنال
عنوان ژورنال: Circulation Research
سال: 2008
ISSN: 0009-7330,1524-4571
DOI: 10.1161/circresaha.107.161679