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An extract of the leaves of the breadfruit Artocarpus altilis (parkinson) fosberg exerts a negative inotropic effect on rat myocardium
Author(s) -
Young Ronald E.,
Williams Lawrence A. D.,
Gardner Michael T.,
Fletcher Cyril K.
Publication year - 1993
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.2650070219
Subject(s) - inotrope , in vivo , chronotropic , medicine , contraction (grammar) , cholinergic , ventricular pressure , chemistry , pharmacology , cardiology , heart rate , blood pressure , biology , microbiology and biotechnology
Abstract Ethyl acetate soluble extracts from the leaves of the breadfruit Artocarpus altilis exerted a weak, negative chronotropic effect ( p <0.05) and significantly reduced left ventricular pulse pressure ( p <0.001) in vivo in the rat. The electrocardiogram maintained a high amplitude QRS complex (ventricular excitation) even when the ventricular pressure pulse was very depressed. On right ventricular myocardial strips, the same extracts produced a significant negative inotropic effect ( p <0.0001). This indicates that the in vivo effects might be due in part, to a direct inotropic effect on the myocardium. An in vivo side effect was extensive intravascular haemolysis and consequent haemoglobinuria which could be caused by the vehicle, the extract, or a combined effect of the two. The mechanism of action of the inotropic agent was not cholinergic, and may involve a decoupling of excitation and contraction.