| Cardiac and coronary function in the Langendorff-perfused mouse heart model. | |
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MedLine Citation:
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PMID: 18723581 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The Langendorff mouse heart model is widely employed in studies of myocardial function and responses to injury (e.g. ischaemia). Nonetheless, marked variability exists in its preparation and functional properties. We examined the impact of early growth (8, 16, 20 and 24 weeks), sex, perfusion fluid [Ca(2+)] and pacing rate on contractile function and responses to 20 min ischaemia followed by 45 min reperfusion. We also assessed the impact of strain, and tested the utility of the model in studying coronary function. Under normoxic conditions, hearts from 8-week-old male C57BL/6 mice (2 mm free perfusate [Ca(2+)], 420 beats min(-1)) exhibited 145 +/- 2 mmHg left ventricular developed pressure (LVDP). Force development declined by approximately 15% (126 +/- 5 mmHg) with a reduction in free [Ca(2+)] to 1.35 mm, and by 25% (108 +/- 3 mmHg) with increased pacing to 600 beats min(-1). While elevated heart rate failed to modify ischaemic outcome, the lower [Ca(2+)] significantly improved contractile recovery (by >30%). We detected minimal sex-dependent differences in normoxic function between 8 and 24 weeks, although age modified contractile function in males (increased LVDP at 24 versus 8 weeks) but not females. Both male and female hearts exhibited age-related reductions in ischaemic tolerance, with a significant decline in recovery evident at 16 weeks in males and later, at 20-24 weeks, in females (versus recoveries in hearts at 8 weeks). Strain also modified tolerance to ischaemia, with similar responses in hearts from C57BL/6, 129/sv, Quackenbush Swiss and FVBN mice, but substantially greater tolerance in BALB/c hearts. In terms of vascular function, baseline coronary flow (20-25 ml min(-1) g(-1)) was 50-60% of maximally dilated flows, and coronary reactive and functional hyperaemic responses were pronounced (up to 4-fold elevations in flow in hearts lacking ventricular balloons). These data indicate that attention to age (and sex) of mice will reduce variability in contractile function and ischaemic responses. Even small differences in perfusion fluid [Ca(2+)] also significantly modify tolerance to ischaemia (whereas modest shifts in heart rate do not impact). Ischaemic responses are additionally strain dependent, with BALB/c hearts displaying greatest intrinsic tolerance. Finally, the model is applicable to the study of vascular reactivity, providing large responses and excellent reproducibility. |
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Authors:
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Melissa E Reichelt; Laura Willems; Benjamin A Hack; Jason N Peart; John P Headrick |
Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't Date: 2008-08-22 |
Journal Detail:
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Title: Experimental physiology Volume: 94 ISSN: 1469-445X ISO Abbreviation: Exp. Physiol. Publication Date: 2009 Jan |
Date Detail:
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Created Date: 2009-01-06 Completed Date: 2009-04-03 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 9002940 Medline TA: Exp Physiol Country: England |
Other Details:
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Languages: eng Pagination: 54-70 Citation Subset: IM |
Affiliation:
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Heart Foundation Research Centre, Griffith University, Southport, Queensland, Australia. mreichelt@ucsd.edu |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Age Factors Animals Coronary Vessels / physiopathology* Disease Models, Animal* Female Heart / physiopathology* Heart Rate / physiology Heart Ventricles / physiopathology Male Mice Mice, Inbred C57BL Mice, Inbred Strains Myocardial Contraction / physiology Myocardial Ischemia / physiopathology* Reperfusion Injury / physiopathology Sex Characteristics |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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