Autor: |
Kiriazis, Helen, Sato, Yoji, Kadambi, Vivek J., Schmidt, Albrecht G., Gerst, Michael J., Hoit, Brian D., Kranias, Evangelia G. |
Předmět: |
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Zdroj: |
Cardiovascular Research; Feb2002, Vol. 53 Issue 2, p372, 10p |
Abstrakt: |
Objective: To determine whether the hyperdynamic phospholamban-knockout hearts are capable of withstanding a chronic aortic stenosis. Methods: The transverse section of the aorta was banded in phospholamban-knockout and their isogenic wild-type mice, which were followed with echocardiography in parallel, along with sham-operated mice, before and at 2.5, 5 and 10 weeks after surgery. Results: Cardiac decompensation was evidenced by the presence of lung congestion in some banded knockouts and wild-types, giving rise to a subset of non-failing and failing hearts within each group. The incidence of heart failure was not genotype-dependent but rather associated with higher heart rates before surgery. The development of left ventricular hypertrophy was similar between knockouts and wild-types and longitudinal assessment of end-diastolic dimension indicated progressive increases after banding, with a greater dilation in failing mice. Fractional shortening was reduced in failing knockouts and wild-types to a similar degree, with an earlier onset in the knockouts. In addition, fractional shortening was decreased in non-failing knockouts but not wild-types. Ejection times shortened after aortic banding particularly for failing hearts. Assessment of the SR Ca2+-ATPase protein levels indicated similar downregulation for failing knockouts and wild-types, while the phospholamban levels were not significantly altered in wild-types. Conclusion: The hyperdynamic phospholamban-knockout hearts are able to compensate against a sustained aortic stenosis similar to wild-types. [Copyright &y& Elsevier] |
Databáze: |
Complementary Index |
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