JPET Introducing ALZET?ew Model 2006 Pump

Home Help [Feedback] [For Subscribers] [Archive] [Search] --
QUICK SEARCH:   [advanced]


     

Journal of Pharmacology And Experimental Therapeutics Fast Forward
First published on May 18, 2005; DOI: 10.1124/jpet.105.087510

This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
jpet.105.087510v1
314/3/945    most recent
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
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 Zhang, J.
Right arrow Articles by Abdel-Rahman, A. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhang, J.
Right arrow Articles by Abdel-Rahman, A. A.


Received for publication April 6, 2005.
Revised May 9, 2005.
Accepted for publication May 10, 2005.

MAPK PHOSPHORYLATION IN THE ROSTRAL VENTROLATERAL MEDULLA PLAYS A KEY ROLE IN IMIDAZOLINE (I1) RECEPTOR MEDIATED HYPOTENSION

Jian Zhang 1 Abdel A. Abdel-Rahman 2*

1 East Carolina University 2 East Carolina University School of Medicine

* Address correspondence to: E-mail: abdelrahmana{at}mail.ecu.edu

Abstract

Our previous study showed that rilmenidine, a selective I1-imidazoline receptor agonist, enhanced the phosphorylation of mitogen-activated protein kinase (MAPKp42/44,) via the phosphatidylcholine-specific phospholipase C (PC-PLC) pathway in pheochromocytoma cell line (PC12). In the present study we tested the hypothesis that enhancement of MAPK phosphorylation in the rostral ventrolateral medulla (RVLM) contributes to the hypotensive response elicited by I1 receptor activation in vivo. Systemic rilmenidine (600 µg/kg, i.v.) elicited hypotension and bradycardia along with significant elevation in MAPKp42/44, detected by immunohistochemistry, in RVLM neurons. To obtain conclusive evidence that the latter response was I1-receptor mediated, similar hypotensive responses were elicited by intracisternal (i.c.) rilmenidine (25 µg/rat) or the highly selective {alpha}2-agonist {alpha}-methylnorepinephrine ({alpha}-MNE, 4 µg/rat). An increase in RVLM MAPKp42/44 occurred only following rilmenidine. Further, pretreatment with efaroxan (0.15 µg/rat, i.c.), a selective I1-imidazoline receptor antagonist, or with PD 98059 (5 µg/rat, i.c.), a selective ERK1/2 inhibitor, significantly attenuated the hypotensive response and the elevation in RVLM MAPKp42/44 elicited by i.c. rilmenidine. The findings suggest that MAPK phosphorylation in the RVLM contributes to the hypotensive response induced by I1 receptor activation and presents in vivo evidence that distinguishes the neuronal responses triggered by the I1-receptor from those triggered by the {alpha}2-adrenergic receptor.


Key words: Hypertension, arterial, Mitogen-activated protein kinase (MAPK), Receptors, adrenergic alpha, Receptors, imidazoline, Rilmenidine, Rostral ventrolateral medulla (RVLM)


This article has been cited by other articles:


Home page
 J. Pharmacol. Exp. Ther.Home page
N. Nassar and A. A. Abdel-Rahman
Brainstem Phosphorylated Extracellular Signal-Regulated Kinase 1/2-Nitric-Oxide Synthase Signaling Mediates the Adenosine A2A-Dependent Hypotensive Action of Clonidine in Conscious Aortic Barodenervated Rats
J. Pharmacol. Exp. Ther., January 1, 2008; 324(1): 79 - 85.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
J. Zhang and A. A. Abdel-Rahman
Inhibition of Nischarin Expression Attenuates Rilmenidine-Evoked Hypotension and Phosphorylated Extracellular Signal-Regulated Kinase 1/2 Production in the Rostral Ventrolateral Medulla of Rats
J. Pharmacol. Exp. Ther., January 1, 2008; 324(1): 72 - 78.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
M. Tanabe, Y. Kino, M. Honda, and H. Ono
Presynaptic I1-Imidazoline Receptors Reduce GABAergic Synaptic Transmission in Striatal Medium Spiny Neurons
J. Neurosci., February 8, 2006; 26(6): 1795 - 1802.
[Abstract] [Full Text] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] --
All ASPET Journals Molecular Pharmacology Pharmacological Reviews
Molecular Interventions Drug Metabolism and Disposition

Copyright © 2005 by the American Society for Pharmacology and Experimental Therapeutics.