Document Detail


Effects of reduced sympathetic activity on myocardial metaiodobenzylguanidine (MIBG) washout.
MedLine Citation:
PMID:  11844024     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
1. Increase in myocardial sympathetic activity contributes markedly to the pathophysiology of conditions such as congestive heart failure and is also associated with myocardial infarction. However, measurement of myocardial sympathetic activity in vivo is difficult. 2. The present study assesses the effectiveness of metaiodobenzylguanidine (MIBG) imaging to characterize modulation of sympathetic activity, as induced by dexmedetomidine, a highly specific alpha-2 adrenoceptor agonist. 3. We imaged washout of [125I]-MIBG from rabbit heart before and during two consecutive 45-min intravenous infusions of dexmedetomidine (10 microg kg(-1) followed by 16 microg kg(-1)) (n=9) or of saline (n=9). 4. Heart rate (HR), and mean blood pressure (BP) were measured before and at the end of each study period. Plasma noradrenaline (NA) was measured before and after study drug infusion. The hearts were then excised and biopsied for MIBG tissue concentration [MIBG] (% kg-dose g(-1)). 5. Relative to saline controls, dexmedetomidine significantly decreased HR, BP, plasma NA and MIBG washout. There was an inverse correlation between MIBG washout and residual [MIBG] in the myocardium (r= -0.75, P < 0.01). 6. These data suggest that a reduction of sympathetic nervous system activity causes a decrease in myocardial MIBG washout in vivo in rabbits, and confirms the usefulness of MIBG scintigraphy as a non-invasive tool to measure changes in myocardial sympathetic activity.
Authors:
D W Gao; P O Talke; M W Dae
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of autonomic pharmacology     Volume:  21     ISSN:  0144-1795     ISO Abbreviation:  J Auton Pharmacol     Publication Date:  2001 Jun 
Date Detail:
Created Date:  2002-02-14     Completed Date:  2002-04-16     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  8106455     Medline TA:  J Auton Pharmacol     Country:  England    
Other Details:
Languages:  eng     Pagination:  159-64     Citation Subset:  IM    
Affiliation:
Department of Radiology, University of California, San Francisco, CA, USA.
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MeSH Terms
Descriptor/Qualifier:
3-Iodobenzylguanidine / diagnostic use,  pharmacokinetics*
Adrenergic alpha-Agonists / pharmacology
Animals
Blood Pressure / drug effects,  physiology
Enzyme Inhibitors / diagnostic use,  pharmacokinetics*
Female
Heart Rate / drug effects,  physiology
Male
Myocardium / metabolism*
Norepinephrine / blood
Rabbits
Sympathetic Nervous System / drug effects,  metabolism,  physiology*
Chemical
Reg. No./Substance:
0/Adrenergic alpha-Agonists; 0/Enzyme Inhibitors; 51-41-2/Norepinephrine; 77679-27-7/3-Iodobenzylguanidine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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