Next Article in Journal
Identification of Diversity-Generating Retroelements in Human Microbiomes
Previous Article in Journal
Complete Proteome of a Quinolone-Resistant Salmonella Typhimurium Phage Type DT104B Clinical Strain
Article Menu
Issue 8 (August) cover image

Export Article

Correction published on 5 September 2014, see Int. J. Mol. Sci. 2014, 15(9), 15766.

Open AccessArticle
Int. J. Mol. Sci. 2014, 15(8), 14220-14233; doi:10.3390/ijms150814220

Functional Cross-Talk between the α1- and β1-Adrenergic Receptors Modulates the Rapidly Activating Delayed Rectifier Potassium Current in Guinea Pig Ventricular Myocytes

Department of Geriatric Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
These authors contributed equally to this work.
*
Author to whom correspondence should be addressed.
Received: 19 May 2014 / Revised: 1 August 2014 / Accepted: 5 August 2014 / Published: 15 August 2014
(This article belongs to the Section Biochemistry, Molecular and Cellular Biology)
View Full-Text   |   Download PDF [3294 KB, uploaded 21 August 2014]   |  

Abstract

The rapidly activating delayed rectifier potassium current (IKr) plays a critical role in cardiac repolarization. Although IKr is known to be regulated by both α1- and β1-adrenergic receptors (ARs), the cross-talk and feedback mechanisms that dictate its response to α1- and β1-AR activation are not known. In the present study, IKr was recorded using the whole-cell patch-clamp technique. IKr amplitude was measured before and after the sequential application of selective adrenergic agonists targeting α1- and β1-ARs. Stimulation of either receptor alone (α1-ARs using 1 μM phenylephrine (PE) or β1-ARs using 10 μM xamoterol (Xamo)) reduced IKr by 0.22 ± 0.03 and 0.28 ± 0.01, respectively. The voltage-dependent activation curve of IKr shifted in the negative direction. The half-maximal activation voltage (V0.5) was altered by −6.35 ± 1.53 and −1.95 ± 2.22 mV, respectively, with no major change in the slope factor (k). When myocytes were pretreated with Xamo, PE-induced reduction in IKr was markedly blunted and the corresponding change in V0.5 was significantly altered. Similarly, when cells were pretreated with PE, Xamo-induced reduction of IKr was significantly attenuated. The present results demonstrate that functional cross-talk between α1- and β1-AR signaling regulates IKr. Such non-linear regulation may form a protective mechanism under excessive adrenergic stimulation. View Full-Text
Keywords: adrenergic receptors; potassium current; cross-talk; arrhythmia adrenergic receptors; potassium current; cross-talk; arrhythmia
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Xu, D.; Wang, S.; Wu, T.-T.; Wang, X.-Y.; Qian, J.; Guo, Y. Functional Cross-Talk between the α1- and β1-Adrenergic Receptors Modulates the Rapidly Activating Delayed Rectifier Potassium Current in Guinea Pig Ventricular Myocytes. Int. J. Mol. Sci. 2014, 15, 14220-14233.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Int. J. Mol. Sci. EISSN 1422-0067 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top