Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2005-5-30
pubmed:abstractText
Recent studies of myoglobin (Mb) knockout (myo-/-) mice have extended our understanding of Mb's diverse functions and have demonstrated a complex array of compensatory mechanisms. The present study was aimed at detailed analysis of cardiac function and exercise endurance in myo-/- mice and at providing evidence for Mb's functional relevance. Myo-/- isolated working hearts display decreased contractility (dP/dtmax 3883+/-351 vs. 4618+/-268 mmHg/sec, myo-/- vs. WT, P<0.005). Due to a shift in sympathetic/parasympathetic tone, heart rate is reduced in conscious myo mice-/- (615+/-33 vs. 645+/-27 bpm, myo-/- vs. WT, P<0.001). Oxygen consumption (VO2) under resting conditions (3082+/-413 vs. 4452+/-552 ml x kg(-1) x h(-1), myo-/- vs. WT, P<0.001) and exercise endurance, as determined by spiroergometry, are decreased (466+/-113 vs. 585+/-153 m, myo-/- vs. WT, P<0.01). Conscious myo-/- mice evaluated by echocardiography display lowered cardiac output (0.64+/-0.06 vs. 0.75+/-0.09 ml x min(-1) x g(-1), myo-/- vs. WT, P<0.001), impaired systolic shortening (60+/-3.5 vs. 65+/-4%, myo-/- vs. WT, P<0.001) and fail to respond to beta1-stimulation. Strikingly, the latter cardiac effects of Mb deficiency can be partially attenuated by NOS inhibition. Loss of Mb results in a distinct phenotype, even under resting conditions, and the importance of oxygen supply and nitric oxide scavenging by Mb is clearly demonstrated at the conscious animal level.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1530-6860
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1015-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Oxygen supply and nitric oxide scavenging by myoglobin contribute to exercise endurance and cardiac function.
pubmed:affiliation
Medizinische Klinik I, RWTH Aachen, Aachen, Germany. mmerx@ukaachen.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't