AJP - Heart AJP: Gastrointestinal and Liver Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol (January 9, 2003). doi:10.1152/ajpheart.00772.2002
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
284/5/H1570    most recent
00772.2002v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
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 Google Scholar
Google Scholar
Right arrow Articles by Rademacher, D. J.
Right arrow Articles by Seagard, J. L
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rademacher, D. J.
Right arrow Articles by Seagard, J. L
Submitted on September 4, 2002
Accepted on January 7, 2003

Microinjection of a Cannabinoid Receptor Antagonist into the NTS Increases Baroreflex Duration in Dogs

David J. Rademacher1, Sachin Patel1, Francis A. Hopp2, Caron Dean2, Cecilia J Hillard1*, and Jeanne L Seagard2

1 Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
2 Department of Anesthesiology, Medical College of Wisconsin and Zablocki Department of Veterans Affairs Medical Center, Milwaukee, Wisconsin, USA

* To whom correspondence should be addressed. E-mail: chillard{at}mcw.edu.

Baroreceptor afferent fibers synapse in the nucleus tractus solitarius (NTS) of the medulla. Neuronal cannabinoid receptors (CB1) are expressed in the NTS and central administration of CB1 receptor agonists affect blood pressure (BP) and heart rate. In addition, there is evidence that endocannabinoids are produced in the brainstem. This study examined whether changes in CB1 receptor activity in the NTS modulated the baroreceptor reflex, contributing to the changes seen in BP and heart rate. Baroreflexes were evoked in anesthetized dogs by pressure ramp stimulations of the isolated carotid sinus before and after microinjection of a CB1 receptor agonist WIN 55,212-2 (1.25-1.50 pmol) or antagonist SR141716 (2.5-3.0 pmol) into cardiovascular regions of the NTS. Microinjection of the SR141716 did not affect baseline blood pressure or baroreflex sensitivity. However, SR141716 significantly prolonged the time needed to return to the baseline level of blood pressure following the pressure ramp. Microinjection of WIN 55,212-2 had no effect on the baroreflex. These data suggest that endocannabinoids can modulate the excitability of NTS neurons involved in the baroreceptor reflex, leading to modulation of baroreflex regulation.




This article has been cited by other articles:


Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
J. W. Polson, R. A. L. Dampney, P. Boscan, A. E. Pickering, and J. F. R. Paton
Differential baroreflex control of sympathetic drive by angiotensin II in the nucleus tractus solitarii
Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2007; 293(5): R1954 - R1960.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
P. Pacher, S. Batkai, D. Osei-Hyiaman, L. Offertaler, J. Liu, J. Harvey-White, A. Brassai, Z. Jarai, B. F. Cravatt, and G. Kunos
Hemodynamic profile, responsiveness to anandamide, and baroreflex sensitivity of mice lacking fatty acid amide hydrolase
Am J Physiol Heart Circ Physiol, August 1, 2005; 289(2): H533 - H541.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
J. L. Seagard, C. Dean, S. Patel, D. J. Rademacher, F. A. Hopp, W. T. Schmeling, and C. J. Hillard
Anandamide content and interaction of endocannabinoid/GABA modulatory effects in the NTS on baroreflex-evoked sympathoinhibition
Am J Physiol Heart Circ Physiol, March 1, 2004; 286(3): H992 - H1000.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 1976 by the American Physiological Society.