Document Detail

The origin of two components in contraction of guinea pig papillary muscle in the presence of noradrenaline.
MedLine Citation:
PMID:  497900     Owner:  NLM     Status:  MEDLINE    
In experiments on isolated guinea pig papillary muscles the effects of verapamil (5 mg/L) and caffeine (1 g/L) on the two-component contraction were investigated. The muscles were continuously superfused with normal Tyrode's solution containing 2 mg of noradrenaline/L at 20--22 degrees C. The first derivative of contractile response and transmembrane action potential were simultaneously recorded. Verapamil suppressed the amplitude of the second component and had no influence on the first component of contraction. Caffeine eliminated the first component and increased the second component of contraction. It was suggested that in the activation of two-component contraction calcium ions from two different pools take part: (1) those released from sarcoplasmic reticulum, and (2) those that crossed a cell membrane during the plateau of the action potential.
K Y Bogdanov; S I Zakharov; L V Rosenshtraukh
Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  Canadian journal of physiology and pharmacology     Volume:  57     ISSN:  0008-4212     ISO Abbreviation:  Can. J. Physiol. Pharmacol.     Publication Date:  1979 Aug 
Date Detail:
Created Date:  1980-01-24     Completed Date:  1980-01-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372712     Medline TA:  Can J Physiol Pharmacol     Country:  CANADA    
Other Details:
Languages:  eng     Pagination:  866-72     Citation Subset:  IM    
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MeSH Terms
Caffeine / pharmacology
Guinea Pigs
Myocardial Contraction / drug effects*
Norepinephrine / pharmacology*
Papillary Muscles / drug effects*
Verapamil / pharmacology
Reg. No./Substance:
51-41-2/Norepinephrine; 52-53-9/Verapamil; 58-08-2/Caffeine

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

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