HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 290/1/H192    most recent 00032.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Ecker, P. M. Articles by Bernstein, D. Search for Related Content PubMed PubMed Citation Articles by Ecker, P. M. Articles by Bernstein, D.

Effect of targeted deletions of ₁- and ₂-adrenergic-receptor subtypes on heart rate variability

¹Department of Pediatrics, Division of Pediatric Cardiology, and the ²Department of Molecular and Cellular Physiology, Stanford University, Stanford, California; and the ³Department of Pediatrics, Veterans General Hospital, Kaohsiung, Taiwan

Submitted 11 January 2005 ; accepted in final form 13 August 2005

-Adrenergic receptors (-ARs) play a major role in regulating heart rate (HR) and contractility in the intact cardiovascular system. Three subtypes (₁, ₂, and ₃) are expressed in heart tissue, and the role of each subtype in regulating cardiac function has previously been determined by using both pharmacological and gene-targeting approaches. However, previous studies have only examined the role of -ARs in the macrolevel regulation of HR. We employed three knockout (KO) mouse lines, ₁-KO, ₂-KO, and ₁/₂ double KO (DL-KO), to examine the role that -AR subtypes play in HR variability (HRV) and in the sympathetic and parasympathetic inputs into HR control. Fast Fourier transformation (FFT) in frequency domain methods of ECG spectral analysis was used to resolve HRV into high- and low-frequency (HF and LF) powers. Resting HR (in beats/min) was decreased in ₁-KO [488 (SD 27)] and DL-KO [495 (SD 12)] mice compared with wild-type [WT; 638 (SD 30)] or ₂-KO [656 (SD 51)] (P < 0.0005) mice. Mice lacking ₁-ARs (1-KO and DL-KO) had increased HRV (as illustrated by the standard deviation of normal R-R intervals) and increased normalized HF and LF powers compared with mice with intact ₁-ARs (WT and ₂-KO). These results demonstrate the differential role of -AR subtypes in regulating autonomic signaling.

chronotropy; sympathetic nervous system; parasympathetic nervous system

This article has been cited by other articles:

				A. P. Kellogg, K. Converso, T. Wiggin, M. Stevens, and R. Pop-Busui Effects of cyclooxygenase-2 gene inactivation on cardiac autonomic and left ventricular function in experimental diabetes Am J Physiol Heart Circ Physiol, February 1, 2009; 296(2): H453 - H461. [Abstract] [Full Text] [PDF]

				Z. Zuberi, L. Birnbaumer, and A. Tinker The role of inhibitory heterotrimeric G proteins in the control of in vivo heart rate dynamics Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2008; 295(6): R1822 - R1830. [Abstract] [Full Text] [PDF]

				S. M. Kim, Y. Huang, Y. Qin, D. Mizel, J. Schnermann, and J. P. Briggs Persistence of circadian variation in arterial blood pressure in {beta}1/{beta}2-adrenergic receptor-deficient mice Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2008; 294(5): R1427 - R1434. [Abstract] [Full Text] [PDF]

				S. J. Swoap, C. Li, J. Wess, A. D. Parsons, T. D. Williams, and J. M. Overton Vagal tone dominates autonomic control of mouse heart rate at thermoneutrality Am J Physiol Heart Circ Physiol, April 1, 2008; 294(4): H1581 - H1588. [Abstract] [Full Text] [PDF]

				N. Spielmann, A. S. Leon, D. C. Rao, T. Rice, J. S. Skinner, T. Rankinen, and C. Bouchard Genome-wide linkage scan for submaximal exercise heart rate in the HERITAGE family study Am J Physiol Heart Circ Physiol, December 1, 2007; 293(6): H3366 - H3371. [Abstract] [Full Text] [PDF]