AJP - Heart Calcium Transients and Cell-Sarcomere
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 284: H2269-H2276, 2003. First published January 16, 2003; doi:10.1152/ajpheart.00774.2002
0363-6135/03 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
284/6/H2269    most recent
00774.2002v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (20)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Michelini, L. C.
Right arrow Articles by Morris, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Michelini, L. C.
Right arrow Articles by Morris, M.
Vol. 284, Issue 6, H2269-H2276, June 2003

Oxytocinergic regulation of cardiovascular function: studies in oxytocin-deficient mice

Lisete C. Michelini1, Marialuisa C. Marcelo2, Janet Amico3, and Mariana Morris2

1 Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, 05508-900, Sao Paulo, Brazil; 2 Department of Pharmacology and Toxicology, Wright State University School of Medicine, Dayton, Ohio 45401; and 3 Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania 15261

Oxytocin (OT) has been implicated in the cardiovascular responses to exercise, stress, and baroreflex adjustments. Studies were conducted to determine the effect of genetic manipulation of the OT gene on blood pressure (BP), heart rate (HR), and autonomic/baroreflex function. OT knockout (OTKO -/-) and control +/+ mice were prepared with chronic arterial catheters. OTKO -/- mice exhibited a mild hypotension (102 ± 3 vs. 110 ± 3 mmHg). Sympathetic and vagal tone were tested using beta 1-adrenergic and cholinergic blockade (atenolol and atropine). Magnitude of sympathetic and vagal tone to the heart and periphery was not significantly different between groups. However, there was an upward shift of sympathetic tone to higher HR values in OTKO -/- mice. This displacement combined with unchanged basal HR led to larger responses to cholinergic blockade (+77 ± 25 vs. +5 ± 15 beats/min, OTKO -/- vs. control +/+ group). There was also an increase in baroreflex gain (-13.1 ± 2.5 vs. -4.1 ± 1.2 beats · min-1 · mmHg-1, OTKO -/- vs. control +/+ group) over a smaller BP range. Results show that OTKO -/- mice are characterized by 1) hypotension, suggesting that OT is involved in tonic BP maintenance; 2) enhanced baroreflex gain over a small BP range, suggesting that OT extends the functional range of arterial baroreceptor reflex; and 3) shift in autonomic balance, indicating that OT reduces the sympathetic reserve.

heart rate; blood pressure; autonomic nervous system; peptides; genetic models; brain


This article has been cited by other articles:


Home page
 Br J AnaesthHome page
J. S. Thomas, S. H. Koh, and G. M. Cooper
Haemodynamic effects of oxytocin given as i.v. bolus or infusion on women undergoing Caesarean section
Br. J. Anaesth., January 1, 2007; 98(1): 116 - 119.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
K. Jackson, H. M. V. Silva, W. Zhang, L. C. Michelini, and J. E. Stern
Exercise Training Differentially Affects Intrinsic Excitability of Autonomic and Neuroendocrine Neurons in the Hypothalamic Paraventricular Nucleus
J Neurophysiol, November 1, 2005; 94(5): 3211 - 3220.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
L. Rinaman, R. R. Vollmer, J. Karam, D. Phillips, X. Li, and J. A. Amico
Dehydration anorexia is attenuated in oxytocin-deficient mice
Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2005; 288(6): R1791 - R1799.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
V. Gross, J. Tank, M. Obst, R. Plehm, K. J. Blumer, A. Diedrich, J. Jordan, and F. C. Luft
Autonomic nervous system and blood pressure regulation in RGS2-deficient mice
Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2005; 288(5): R1134 - R1142.
[Abstract] [Full Text] [PDF]

Home page
 HypertensionHome page
K. Rigatto, R. Puryear, I. Bernatova, and M. Morris
Salt Appetite and the Renin-Angiotensin System: Effect of Oxytocin Deficiency
Hypertension, October 1, 2003; 42(4): 793 - 797.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online
Copyright © 2003 by the American Physiological Society.