Document Detail


Role of aging on electrical, mechanical, and coronary modification induced by ouabain and epinine in isolated rat heart.
MedLine Citation:
PMID:  8174156     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: The contractile response to digitalis and beta adrenoceptor agonists is lower in the senescent than in the adult myocardium, while the development of ventricular arrhythmias is increased. The aim of this study was to examine the effects of aging on cardiac response to digitalis and an adrenergic agonist used clinically. METHODS: The electrical and mechanical responses were tested in isolated and perfused hearts from 3-24 month old rats receiving 15 min infusion of digitalis drug (ouabain, 6 x 10(-5) M) alone, and after 5 min of beta adrenoceptor agonist drug (epinine, 1.5 x 10(-7) M). RESULTS: Ouabain action was associated with a rise in left ventricular end diastolic pressure (p < 0.01) which increased progressively with aging, and with an elevation of left ventricular developed pressure (p < 0.01) which decreased progressively with aging. Epinine induced a reduction of left ventricular end diastolic pressure (p < 0.01) and a rise in left ventricular developed pressure (p < 0.01) but both effects decreased progressively with aging. Ouabain reduced coronary flow and this decrease was more pronounced with aging (p < 0.01), while epinine caused an increase (p < 0.01) that diminished in older hearts. Ouabain given after epinine resulted in a greater increase in left ventricular end diastolic pressure than epinine (p < 0.01) but lower than that caused by ouabain alone (p < 0.01), a greater increase in left ventricular developed pressure than epinine and ouabain (p < 0.01), and a smaller reduction of coronary flow rate than ouabain alone (p < 0.01). All these effects, however, diminished progressively with aging. Arrhythmia scores were higher during ouabain than in control (p < 0.01) and in epinine treated hearts (p < 0.01); pretreatment with epinine did not modify arrhythmia score during ouabain administration. The number and severity of arrhythmias, however, increased with aging in all groups. CONCLUSIONS: Aging has a negative effect on both the positive inotropic and the arrhythmogenic effects of ouabain and epinine, although these phenomena are more pronounced during ouabain administration. However, when the two drugs are given simultaneously, epinine does not modify the arrhythmogenic effect of ouabain but reduces some of its deleterious haemodynamic effects.
Authors:
P Abete; P Caccese; P Landino; A Cioppa; R Abate; F Ciaburri; P Ferrara; L De Caprio; N Ferrara; F Rengo
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Cardiovascular research     Volume:  28     ISSN:  0008-6363     ISO Abbreviation:  Cardiovasc. Res.     Publication Date:  1994 Mar 
Date Detail:
Created Date:  1994-06-08     Completed Date:  1994-06-08     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0077427     Medline TA:  Cardiovasc Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  358-64     Citation Subset:  IM    
Affiliation:
Istituto di Medicina Interna, Cardiologia e Chirurgia Cardiovascolare, Facoltà di Medicina e Chirurgia, Università degli Studi di Napoli Federico II, Italy.
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MeSH Terms
Descriptor/Qualifier:
Aging / physiology*
Animals
Coronary Circulation / drug effects
Deoxyepinephrine / pharmacology*
Heart / drug effects,  physiopathology*
Heart Rate / drug effects,  physiology
Male
Myocardial Contraction / drug effects,  physiology
Ouabain / pharmacology*
Perfusion
Rats
Rats, Wistar
Ventricular Function, Left / drug effects
Chemical
Reg. No./Substance:
501-15-5/Deoxyepinephrine; 630-60-4/Ouabain

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


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