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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-3-27
pubmed:abstractText
Diabetic cardiomyopathy is characterized by reduced cardiac contractility due to direct changes in heart muscle function independent of vascular disease. An important contributor to contractile dysfunction in the diabetic state is an impaired sarcoplasmic reticulum (SR) function, leading to disturbed intracellular calcium handling. We investigated whether overexpression of the SR calcium pump (SERCA2a) in transgenic mice could reduce the impact of diabetes on the development of cardiomyopathy. Diabetes was induced by streptozotocin injection (200 mg/kg), and left ventricular (LV) function was analyzed in isolated hearts 3 weeks later. In diabetic hearts systolic LV pressure was decreased by 15% and maximum speed of relaxation (-dP/dt) by 34%. Functional changes were also assessed in isolated papillary muscles. Active force was reduced by 61% and maximum speed of relaxation by 65% in the diabetic state. The contractile impairment was accompanied by a 30% decrease in SERCA2a protein in diabetic mice. We investigated whether increased SERCA2a expression in transgenic SERCA2a-overexpressing mice could compensate for the diabetes-induced decrease in cardiac function. Under normal conditions, SERCA2a overexpressors show improved contractile performance relative to wild-type (WT) mice (-dP/dt: 3,169 vs. 2,559 mmHg/s, respectively). Measurement of LV function in hearts from diabetic SERCA2a mice revealed systolic and diastolic functions that were similar to WT control mice and markedly improved relative to diabetic WT mice (-dP/dt: 2,534 vs. 1,690 mmHg/s in diabetic SERCA2a vs. diabetic WT mice, respectively). Similarly, the contractile behavior of isolated papillary muscles from diabetic SERCA2a mice was not different from that of control mice. SERCA2a protein expression was higher (60%) in diabetic SERCA2a mice than WT diabetic mice. These results indicate that overexpression of SERCA2a can protect diabetic hearts from severe contractile dysfunction, presumably by improving the calcium sequestration of the SR.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0012-1797
pubmed:author
pubmed:issnType
Print
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1166-71
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:11916940-Animals, pubmed-meshheading:11916940-Body Weight, pubmed-meshheading:11916940-Calcium-Transporting ATPases, pubmed-meshheading:11916940-Cardiomyopathies, pubmed-meshheading:11916940-Diabetes Mellitus, Experimental, pubmed-meshheading:11916940-Gene Expression Regulation, Enzymologic, pubmed-meshheading:11916940-Heart, pubmed-meshheading:11916940-Mice, pubmed-meshheading:11916940-Myocardial Contraction, pubmed-meshheading:11916940-Myocardium, pubmed-meshheading:11916940-Organ Size, pubmed-meshheading:11916940-Papillary Muscles, pubmed-meshheading:11916940-Perfusion, pubmed-meshheading:11916940-Sarcoplasmic Reticulum, pubmed-meshheading:11916940-Sarcoplasmic Reticulum Calcium-Transporting ATPases, pubmed-meshheading:11916940-Transcription, Genetic, pubmed-meshheading:11916940-Vasodilation
pubmed:year
2002
pubmed:articleTitle
Overexpression of the sarcoplasmic reticulum Ca(2+)-ATPase improves myocardial contractility in diabetic cardiomyopathy.
pubmed:affiliation
Department of Medicine, University of California, San Diego, California 92093-0618, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't