| Effects of chronic heart failure in rats on the recovery of microvascular PO2 after contractions in muscles of opposing fibre type. | |
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MedLine Citation:
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PMID: 15131070 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Chronic heart failure (CHF) impairs muscle O2 delivery (QO2) and, at a given O2 uptake (VO2), lowers microvascular O2 pressures (PmvO2: determined by the QO2-to-VO2 ratio), which may impair recovery of high-energy phosphates following exercise. Because CHF preferentially decreases QO2 to slow-twitch muscles, we hypothesized that recovery PmvO2 kinetics would be slowed to a greater extent in soleus (SOL: approximately 84% type I fibres) than in peroneal (PER: approximately 14% type I) muscles of CHF rats. PmvO2 dynamics were determined in SOL and PER muscles of control (CON: n= 6; left ventricular end-diastolic pressure, LVEDP: approximately 3 mmHg), moderate CHF (MOD: n= 7; LVEDP: approximately 11 mmHg) and severe CHF (SEV: n= 4; LVEDP: approximately 25 mmHg) following cessation of electrical stimulation (180 s; 1 Hz). In PER, neither the recovery PmvO2 values nor the mean response time (MRT; a weighted average of the time to 63% of the overall response) were altered by CHF (CON: 66.8 +/- 8.0, MOD: 72.4 +/- 11.8, SEV: 69.1 +/- 9.5 s). In marked contrast, SOL PmvO2, at recovery onset, was reduced significantly in the SEV group ( approximately 6 Torr) and PmvO2 MRT was slowed with increased severity of CHF (CON: 45.1 +/- 5.3, MOD: 63.2 +/- 9.4, SEV: 82.6 +/- 12.3 s; P < 0.05 CON vs. MOD and SEV). These data indicate that CHF slows PmvO2 recovery following contractions and lowers capillary O2 driving pressure in slow-twitch SOL, but not in fast-twitch PER muscle. These results may explain, in part, the slowed recovery kinetics (phosphocreatine and VO2) and pronounced fatigue following muscular work in CHF patients. |
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Authors:
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Paul McDonough; Brad J Behnke; Timothy I Musch; David C Poole |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. Date: 2004-05-06 |
Journal Detail:
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Title: Experimental physiology Volume: 89 ISSN: 0958-0670 ISO Abbreviation: Exp. Physiol. Publication Date: 2004 Jul |
Date Detail:
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Created Date: 2004-07-07 Completed Date: 2004-10-18 Revised Date: 2007-11-15 |
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: 473-85 Citation Subset: IM |
Copyright Information:
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Copyright 2004 The Physiological Society |
Affiliation:
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Departments of Anatomy, Physiology and Kinesiology, 129 Coles Hall, Kansas State University, Manhattan, KS 66506-5802, USA. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Chronic Disease Female Heart Failure / physiopathology* Microcirculation / physiology Muscle Contraction / physiology* Muscle Fibers, Slow-Twitch / physiology Muscle, Skeletal / blood supply, innervation, physiology* Oxygen / blood* Oxygen Consumption / physiology Partial Pressure Peroneal Nerve / physiology Phosphocreatine / metabolism Rats Rats, Sprague-Dawley |
| Grant Support | |
ID/Acronym/Agency:
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AG-19228/AG/NIA NIH HHS; HL-50306/HL/NHLBI NIH HHS; HL-67619/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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67-07-2/Phosphocreatine; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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