Journal of Applied Physiology AJP: Cell Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 99: 587-592, 2005. First published March 31, 2005; doi:10.1152/japplphysiol.00147.2005
8750-7587/05 $8.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow All Versions of this Article:
99/2/587    most recent
00147.2005v1
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
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 (8)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Masuki, S.
Right arrow Articles by Eisenach, J. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Masuki, S.
Right arrow Articles by Eisenach, J. H.

Selective {alpha}2-adrenergic properties of dexmedetomidine over clonidine in the human forearm

Shizue Masuki,1 Frank A. Dinenno,2 Michael J. Joyner,1 and John H. Eisenach1

1Department of Anesthesiology, Mayo Clinic, College of Medicine, Rochester, Minnesota; and 2Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado

Submitted 4 February 2005 ; accepted in final form 24 March 2005

We tested the hypothesis that dexmedetomidine (Dex) has greater {alpha}2- vs. {alpha}1 selectivity than clonidine and causes more {alpha}2-selective vasoconstriction in the human forearm. After local {beta}-adrenergic blockade with propranolol, forearm blood flow (plethysmography) responses to brachial artery administration of Dex, clonidine, and phenylephrine ({alpha}1-agonist) were determined in healthy young adults before and after {alpha}2-blockade with yohimbine (n = 10) or {alpha}1-blockade with prazosin (n = 9). Yohimbine had no effect on phenylephrine-mediated vasoconstriction but blunted Dex-mediated vasoconstriction (mean ± SE: –41 ± 5 vs. –11 ± 2%; before vs. after yohimbine) more than clonidine-mediated vasoconstriction (–39 ± 5 vs. –28 ± 4%; before vs. after yohimbine) (P < 0.02). Prazosin blunted phenylephrine-mediated vasoconstriction (–39 ± 4 vs. –8 ± 2%; before vs. after prazosin) but had similar effects on both Dex- (–30 ± 4 vs. –39 ± 6%; before vs. after prazosin) and clonidine-mediated vasoconstriction (–29 ± 3 vs. –41 ± 7%; before vs. after prazosin) (P > 0.7). Both Dex and clonidine reduced deep forearm venous norepinephrine concentrations to a similar extent (–59 ± 12 vs. –55 ± 10 pg/ml; Dex vs. clonidine, P > 0.6); this effect was abolished by yohimbine and blunted by prazosin. These results suggest that Dex causes more {alpha}2-selective vasoconstriction in the forearm than clonidine. The similar vasoconstrictor responses to both drugs after prazosin might be explained by the presynaptic effects on norepinephrine release.

forearm blood flow; sympathetic nervous system; vasoconstriction; resistance vessels


Address for reprint requests and other correspondence: J. H. Eisenach, Dept. of Anesthesiology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905 (eisenach.john{at}mayo.edu)




This article has been cited by other articles:


Home page
 Anesth. Analg.Home page
T. Yoshitomi, A. Kohjitani, S. Maeda, H. Higuchi, M. Shimada, and T. Miyawaki
Dexmedetomidine Enhances the Local Anesthetic Action of Lidocaine via an {alpha}-2A Adrenoceptor
Anesth. Analg., July 1, 2008; 107(1): 96 - 101.
[Abstract] [Full Text] [PDF]

Home page
 HypertensionHome page
D. Kurnik, M. Muszkat, G. G. Sofowora, E. A. Friedman, W. D. Dupont, M. Scheinin, A. J.J. Wood, and C. M. Stein
Ethnic and Genetic Determinants of Cardiovascular Response to the Selective {alpha}2-Adrenoceptor Agonist Dexmedetomidine
Hypertension, February 1, 2008; 51(2): 406 - 411.
[Abstract] [Full Text] [PDF]

Home page
 J Am Coll CardiolHome page
D. V. Menon, Z. Wang, P. J. Fadel, D. Arbique, D. Leonard, J.-L. Li, R. G. Victor, and W. Vongpatanasin
Central Sympatholysis as a Novel Countermeasure for Cocaine-Induced Sympathetic Activation and Vasoconstriction in Humans
J. Am. Coll. Cardiol., August 14, 2007; 50(7): 626 - 633.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
E. G. Smith, W. F. Voyles, B. S. Kirby, R. R. Markwald, and F. A. Dinenno
Ageing and leg postjunctional {alpha}-adrenergic vasoconstrictor responsiveness in healthy men
J. Physiol., July 1, 2007; 582(1): 63 - 71.
[Abstract] [Full Text] [PDF]

Home page
 Anesth. Analg.Home page
J. N. Pratap, R. K. Shankar, and T. Goroszeniuk
Co-injection of Clonidine Prolongs the Anesthetic Effect of Lidocaine Skin Infiltration by a Peripheral Action
Anesth. Analg., April 1, 2007; 104(4): 982 - 983.
[Abstract] [Full Text] [PDF]

Home page
 Anesth. Analg.Home page
G. Cucchiaro and A. Ganesh
The Effects of Clonidine on Postoperative Analgesia After Peripheral Nerve Blockade in Children
Anesth. Analg., March 1, 2007; 104(3): 532 - 537.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
S. Masuki, J. H. Eisenach, F. A. Dinenno, and M. J. Joyner
Reduced forearm {alpha}1-adrenergic vasoconstriction is associated with enhanced heart rate fluctuations in humans
J Appl Physiol, March 1, 2006; 100(3): 792 - 799.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online
Copyright © 2005 by the American Physiological Society.