Manipulation of papillary muscle cyclic nucleotides during anoxia-reoxygenation: Effects on contractility

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dc.contributor.authorUpton J.J.
dc.contributor.authorHuisamen B.
dc.contributor.authorLochner A.
dc.date.accessioned2011-05-15T15:56:44Z
dc.date.available2011-05-15T15:56:44Z
dc.date.issued2002
dc.description.abstractEndogenous nitric oxide and the accompanying cGMP formation has been postulated to play a role in the pathophysiology of myocardial anoxia-reoxygenation. A direct relationship between cGMP and the alterations observed in contractility under these conditions has never been demonstrated. In this study, cGMP in rat papillary muscles during anoxia and reoxygenation was correlated with mechanical function. Isolated papillary muscles were stimulated continuously and made anoxic for 40 min after a 2-hour stabilisation period. Anoxia caused an abbreviated contraction curve by decreasing the maximum contraction strength, time to peak contraction and relaxation time, accompanied by a significant decrease in tissue cGMP and cAMP levels (controls: 29.09 ± 1.62 and 568.8 ± 35.65; anoxia: 16.62 ± 1.51 and 403.3 ± 30.19 pmoles/gww), which partially returned to pre-anoxic values upon reoxygenation. cGMP levels were significantly elevated by addition of 8-Br-cGMP (a cGMP analogue), but this elevation (154.4 ± 20.89 pmoles/gww), had no effects on the contractility pattern of muscles during normoxia, anoxia or reoxygenation, suggesting that in isolated ventricular muscle, cGMP levels play a minor role in regulating muscle contractility.
dc.description.versionArticle
dc.identifier.citationCardiovascular Journal of South Africa
dc.identifier.citation13
dc.identifier.citation1
dc.identifier.issn10159657
dc.identifier.urihttp://hdl.handle.net/10019.1/10009
dc.subject8 bromo cyclic GMP
dc.subjectcyclic GMP
dc.subjectcyclic nucleotide
dc.subjectnitric oxide
dc.subjectanimal tissue
dc.subjectanoxia
dc.subjectarticle
dc.subjectcontrolled study
dc.subjectheart muscle contractility
dc.subjectheart muscle ischemia
dc.subjectheart muscle reperfusion
dc.subjectheart papillary muscle
dc.subjectheart ventricle wall
dc.subjectinotropism
dc.subjectmale
dc.subjectmuscle contraction
dc.subjectnonhuman
dc.subjectpathophysiology
dc.subjectrat
dc.subjectreoxygenation
dc.subjecttissue metabolism
dc.subjecttissue oxygenation
dc.subjectAnimals
dc.subjectCell Hypoxia
dc.subjectCyclic AMP
dc.subjectCyclic GMP
dc.subjectElectric Stimulation
dc.subjectMale
dc.subjectMyocardial Contraction
dc.subjectNucleotides, Cyclic
dc.subjectPapillary Muscles
dc.subjectRats
dc.subjectRats, Wistar
dc.subjectTime Factors
dc.titleManipulation of papillary muscle cyclic nucleotides during anoxia-reoxygenation: Effects on contractility
dc.typeArticle
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