Document Detail


Double-peaked positive chronotropic responses of isolated and cross-perfused dog atria to ATP.
MedLine Citation:
PMID:  6668765     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effects of a large amount of adenosine and ATP (100 to 3000 micrograms) were investigated on sinus rate and developed tension, using the isolated dog atrium which was perfused with arterial blood from a heparinized donor dog. Each of the substances used for study was administered into the cannulated sinus node artery of the isolated atrium. Adenosine caused monophasic negative chronotropic and inotropic effects in a dose-related manner. However, ATP induced two-peaked positive chronotropic phases during a long-lasting negative chronotropic phase, i.e., initially, brief positive (t-1) effects and secondarily, relatively longer positive chronotropic (t-2) effects. These responses were repetitively induced during the experiment. The t-1 and t-2 were not influenced by treatment with propranolol which significantly blocked the positive chronotropic effect of norepinephrine. Aminophylline treatment significantly suppressed t-2 but not t-1. Quinidine (100-1000 micrograms) did not affect either the t-1 or t-2. It is suggested that ATP-induced tachycardia in the dog is partially due to activation of the P1-purinoceptors named by Burnstock.
Authors:
S Chiba; M Kobayashi; M Shimotori
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Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  Japanese journal of pharmacology     Volume:  33     ISSN:  0021-5198     ISO Abbreviation:  Jpn. J. Pharmacol.     Publication Date:  1983 Dec 
Date Detail:
Created Date:  1984-04-02     Completed Date:  1984-04-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2983305R     Medline TA:  Jpn J Pharmacol     Country:  JAPAN    
Other Details:
Languages:  eng     Pagination:  1191-7     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Adenosine / pharmacology
Adenosine Triphosphate / pharmacology*
Aminophylline / pharmacology
Animals
Dogs
Female
Heart Rate / drug effects*
Male
Myocardial Contraction / drug effects
Perfusion
Propranolol / pharmacology
Quinidine / pharmacology
Stimulation, Chemical
Chemical
Reg. No./Substance:
317-34-0/Aminophylline; 525-66-6/Propranolol; 56-54-2/Quinidine; 56-65-5/Adenosine Triphosphate; 58-61-7/Adenosine

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


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