Prolonged Action Potential and After depolarizations Are Not due to Changes in Potassium Currents in NOS3 Knockout Ventricular Myocytes
Joint Authors
Carnes, Cynthia A.
Ziolo, Mark T.
Huang, Xin
He, Quanhua
Bonilla, Ingrid M.
Wang, Honglan
Kohr, Mark J.
Source
Journal of Signal Transduction
Issue
Vol. 2012, Issue 2012 (31 Dec. 2012), pp.1-8, 8 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2012-08-28
Country of Publication
Egypt
No. of Pages
8
Main Subjects
Abstract EN
Ventricular myocytes deficient in endothelial nitric oxide synthase (NOS3−/−) exhibit prolonged action potential (AP) duration and enhanced spontaneous activity (early and delayed afterdepolarizations) during β-adrenergic (β-AR) stimulation.
Studies have shown that nitric oxide is able to regulate various K+ channels.
Our objective was to examine if NOS3-/- myocytes had altered K+ currents.
APs, transient outward (Ito), sustained (IKsus), and inward rectifier (IK1) K+ currents were measured in NOS3-/- and wild-type (WT) myocytes.
During β-AR stimulation, AP duration (measured as 90% repolarization-APD90) was prolonged in NOS3−/− compared to WT myocytes.
Nevertheless, we did not observe differences in Ito, IKsus, or IK1 between WT and NOS3−/− myocytes.
Our previous work showed that NOS3−/− myocytes had a greater Ca2+ influx via L-type Ca2+ channels with β-AR stimulation.
Thus, we measured β-AR-stimulated SR Ca2+ load and found a greater increase in NOS3−/− versus WT myocytes.
Hence, our data suggest that the prolonged AP in NOS3−/− myocytes is not due to changes in Ito, IKsus, or IK1.
Furthermore, the increase in spontaneous activity in NOS3−/− myocytes may be due to a greater increase in SR Ca2+ load.
This may have important implications for heart failure patients, where arrhythmias are increased and NOS3 expression is decreased.
American Psychological Association (APA)
Wang, Honglan& Bonilla, Ingrid M.& Huang, Xin& He, Quanhua& Kohr, Mark J.& Carnes, Cynthia A.…[et al.]. 2012. Prolonged Action Potential and After depolarizations Are Not due to Changes in Potassium Currents in NOS3 Knockout Ventricular Myocytes. Journal of Signal Transduction،Vol. 2012, no. 2012, pp.1-8.
https://search.emarefa.net/detail/BIM-487800
Modern Language Association (MLA)
Wang, Honglan…[et al.]. Prolonged Action Potential and After depolarizations Are Not due to Changes in Potassium Currents in NOS3 Knockout Ventricular Myocytes. Journal of Signal Transduction No. 2012 (2012), pp.1-8.
https://search.emarefa.net/detail/BIM-487800
American Medical Association (AMA)
Wang, Honglan& Bonilla, Ingrid M.& Huang, Xin& He, Quanhua& Kohr, Mark J.& Carnes, Cynthia A.…[et al.]. Prolonged Action Potential and After depolarizations Are Not due to Changes in Potassium Currents in NOS3 Knockout Ventricular Myocytes. Journal of Signal Transduction. 2012. Vol. 2012, no. 2012, pp.1-8.
https://search.emarefa.net/detail/BIM-487800
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-487800