| Influence of a period of inactivity on the duration of post-rest action potentials of the mammalian working ventricular myocardium in correlation to the preceding stimulation frequency. | |
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MedLine Citation:
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PMID: 2962206 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Experiments were carried out on the working right ventricular myocardium of adult cats, guinea-pigs and rabbits. Membrane voltage was recorded by the glass microelectrode technique and the preparations were stimulated with frequencies of 5, 1 and 0.2 Hz. After a steady state had been reached, a pause (TP) lasting 10-600 s was interpolated. The influence of TP on the duration (D) of post-rest action potentials (AP) was studied; the effect of the pause was measured at electric zero level (D0) and at further repolarization levels (-20, -40 and -60 mV, given here as D-20, D-40 and D-60). At 1 and 0.2 Hz frequency, the cat myocardium displayed lengthening of the AP proportional to the duration of the pause; at 5 Hz frequency, D0 reacted by lengthening up to TP = 120 s and to further pauses by slight shortening. D-60, at all frequencies, lengthened throughout the whole of the given TP range. The rabbit myocardium, at all the given frequencies, reacted up to TP = 60-120 s by marked shortening of post-rest AP at all repolarization levels; with longer pauses the AP lengthened. At 5 Hz frequency the guinea-pig myocardium reacted similarly to the cat myocardium; at the lower stimulation frequencies, the pause-induced changes in the post-rest AP were less strongly expressed. In all the given types of myocardium, the most pronounced post-rest AP reactions were those at electric zero level (the plateau phase of the AP); towards more negative repolarization values and with lower pre-pause stimulation frequencies they were less strongly expressed.(ABSTRACT TRUNCATED AT 250 WORDS) |
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Authors:
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P Pucelík; P Králícek; M Holická; M Lässigová; P Fiala |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Physiologia Bohemoslovaca Volume: 36 ISSN: 0369-9463 ISO Abbreviation: Physiol Bohemoslov Publication Date: 1987 |
Date Detail:
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Created Date: 1988-01-25 Completed Date: 1988-01-25 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 0175317 Medline TA: Physiol Bohemoslov Country: CZECHOSLOVAKIA |
Other Details:
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Languages: eng Pagination: 394-402 Citation Subset: IM |
Affiliation:
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Department of Physiology, Faculty of Medicine, Charles University, Plzen. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Action Potentials Animals Cats Electric Stimulation Female Guinea Pigs Heart / physiology* Male Rabbits Species Specificity Time Factors Ventricular Function |
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