| Reduction of regional contractile function by preconditioning ischemia does not play a permissive role in the infarct size-limitation by the preconditioning. | |
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MedLine Citation:
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PMID: 8147824 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Although previous studies have shown that preconditioning cannot be explained by concurrent myocardial stunning alone, it remains unclear whether reduction of contractile function by preconditioning ischemia is required for its cardioprotective effect. The present study examined whether preconditioning occurs in the absence of regional contractile dysfunction. In the first series of experiments, rabbits received two cycles of 2-min coronary occlusion separated by 5-min reperfusion, with or without dobutamine infusion (10 micrograms/kg/min, i.v.) commencing before the onset of ischemia. Regional thickening fraction measured by epicardial Doppler sensor was 72.8 +/- 4.7% of baseline (mean +/- SEM) in the untreated group and 102.9 +/- 3.1% in the dobutamine group at the end of the second cycle of ischemia/reperfusion. In the second series of the study, four groups of rabbits underwent 30-min coronary occlusion and reperfusion. The control group was untreated, and the PC group was preconditioned with two cycles of 2-min ischemia/5-min reperfusion before the 30-min ischemia. The PC-DOB group received both preconditioning and dobutamine infusion (10 micrograms/kg/min, i.v.), which was started 5 min before the preconditioning and continued for 19 min. The DOB group was given dobutamine infusion like the PC-DOB group, but was not preconditioned. After 72-h reperfusion, infarct size and area at risk were determined by histology and fluorescent particles, respectively. Infarct sizes in the PC and PC-DOB groups (25.0 +/- 3.4% and 22.7 +/- 3.3% of area at risk, respectively) were significantly smaller than that in the control group (48.2 +/- 2.6%). In the DOB groups, infarct size (43.5 +/- 4.0%) was similar to the control value. Infusion of dobutamine at a dose sufficient to abolish the contractile dysfunction which would have been induced by ischemic preconditioning did not attenuate the infarct size-limiting effect of preconditioning. Thus, it is unlikely that reduction of contractile function plays a permissive role in the appearance of the cardioprotective effect of preconditioning. |
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Authors:
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M Goto; T Miura; M Itoya; J Sakamoto; O Iimura |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Basic research in cardiology Volume: 88 ISSN: 0300-8428 ISO Abbreviation: Basic Res. Cardiol. Publication Date: 1993 Nov-Dec |
Date Detail:
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Created Date: 1994-05-02 Completed Date: 1994-05-02 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0360342 Medline TA: Basic Res Cardiol Country: GERMANY |
Other Details:
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Languages: eng Pagination: 594-606 Citation Subset: IM |
Affiliation:
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Second Department of Internal Medicine, Sapporo Medical University, School of Medicine. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Dobutamine / pharmacology Hemodynamics Male Myocardial Contraction* Myocardial Infarction / pathology*, physiopathology* Myocardial Stunning* Myocardium / pathology Rabbits |
| Chemical | |
Reg. No./Substance:
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34368-04-2/Dobutamine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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