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: 289/5/H1985    most recent 00430.2005v1 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 (8) Citing Articles via Google Scholar Google Scholar Articles by Padley, J. R. Articles by Goodchild, A. K. Search for Related Content PubMed PubMed Citation Articles by Padley, J. R. Articles by Goodchild, A. K.

Impaired cardiac and sympathetic autonomic control in rats differing in acetylcholine receptor sensitivity

¹Hypertension and Stroke Research Laboratories, Department of Physiology, University of Sydney and Department of Neurosurgery, Royal North Shore Hospital, St. Leonards New South Wales, Australia; and ²Skipper Bowles Center for Alcohol Studies, Department of Psychiatry, University of North Carolina, Chapel Hill, North Carolina

Submitted 29 April 2005 ; accepted in final form 6 June 2005

Acetylcholine receptors (AChR) are important in premotor and efferent control of autonomic function; however, the extent to which cardiovascular function is affected by genetic variations in AChR sensitivity is unknown. We assessed heart rate variability (HRV) and baroreflex sensitivity (BRS) in rats bred for resistance (FRL) or sensitivity (FSL) to cholinergic agents compared with Sprague-Dawley rats (SD), confirmed by using hypothermic responses evoked by the muscarinic agonist oxotremorine (0.2 mg/kg ip) (n 9 rats/group). Arterial pressure, ECG, and splanchnic sympathetic (SNA) and phrenic (PNA) nerve activities were acquired under anesthesia (urethane 1.3 g/kg ip). HRV was assessed in time and frequency domains from short-term R-R interval data, and spontaneous heart rate BRS was obtained by using a sequence method at rest and after administration of atropine methylnitrate (mATR, 2 mg/kg iv). Heart rate and SNA baroreflex gains were assessed by using conventional pharmacological methods. FRL and FSL were normotensive but displayed elevated heart rates, reduced HRV and HF power, and spontaneous BRS compared with SD. mATR had no effect on these parameters in FRL or FSL, indicating reduced cardiovagal tone. FSL exhibited reduced PNA frequency, longer baroreflex latency, and reduced baroreflex gain of heart rate and SNA compared with FRL and SD, indicating in FSL dual impairment of cardiac and circulatory baroreflexes. These findings show that AChR resistance results in reduced cardiac muscarinic receptor function leading to cardiovagal insufficiency. In contrast, AChR sensitivity results in autonomic and respiratory abnormalities arising from alterations in central muscarinic and or other neurotransmitter receptors.

heart rate variability; baroreflex sensitivity; Flinders Sensitive line; Flinders Resistant line

This article has been cited by other articles:

				A. C. Arnold, H. A. Shaltout, P. E. Gallagher, and D. I. Diz Leptin Impairs Cardiovagal Baroreflex Function at the Level of the Solitary Tract Nucleus Hypertension, November 1, 2009; 54(5): 1001 - 1008. [Abstract] [Full Text] [PDF]

				S. B. G. Abbott and P. M. Pilowsky Galanin microinjection into rostral ventrolateral medulla of the rat is hypotensive and attenuates sympathetic chemoreflex Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2009; 296(4): R1019 - R1026. [Abstract] [Full Text] [PDF]

				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]

				M. Henze, D. Hart, A. Samarel, J. Barakat, L. Eckert, and K. Scrogin Persistent alterations in heart rate variability, baroreflex sensitivity, and anxiety-like behaviors during development of heart failure in the rat Am J Physiol Heart Circ Physiol, July 1, 2008; 295(1): H29 - H38. [Abstract] [Full Text] [PDF]

				C. M. Hildreth, J. R. Padley, P. M. Pilowsky, and A. K. Goodchild Impaired serotonergic regulation of heart rate may underlie reduced baroreflex sensitivity in an animal model of depression Am J Physiol Heart Circ Physiol, January 1, 2008; 294(1): H474 - H480. [Abstract] [Full Text] [PDF]

				A. J. Hautala, T. Rankinen, A. M. Kiviniemi, T. H. Makikallio, H. V. Huikuri, C. Bouchard, and M. P. Tulppo Heart rate recovery after maximal exercise is associated with acetylcholine receptor M2 (CHRM2) gene polymorphism Am J Physiol Heart Circ Physiol, July 1, 2006; 291(1): H459 - H466. [Abstract] [Full Text] [PDF]