| Autor: |
Ritter, Oliver, Luther, Hans Peter, Haase, Hannelore, Baltas, Leonidas G., Baumann, Gert, Schulte, Hagen Dieter, Morano, Ingo |
| Zdroj: |
Journal of Molecular Medicine; Sep1999, Vol. 77 Issue 9, p677-685, 9p |
| Abstrakt: |
The adult rodent heart adapts to increased work load by reexpression of its fetal genes, for example, β-myosin heavy chain (MHC), in order to improve contractile function. However, the human ventricle regulates contractility by expression of atrial essential myosin light chain (ALC-1) rather than β-MHC. We evaluated the impact of both mechanisms in patients with hypertrophic cardiomyopathy. MHC isoform expression was quantified at the mRNA and protein levels by reverse transcriptase polymerase chain reaction and immunoblotting, respectively. Although α-MHC mRNA was detected in control and hypertrophied human ventricular tissue, α-MHC protein was not observed. Similarly, we investigated the expression of ALC-1 by two-dimensional polyacrylamide gel electrophoresis and the clinical and hemodynamic parameters of the patients with hypertrophic cardiomyopathy. We found a significant positive correlation between ALC-1 protein expression and d P/d t max in the hypertrophied human ventricle in vivo. Correlations between d P/d t max and expression of protein for the ryanodine receptor and L-type Ca2+ channel were excluded. Our data suggest that reexpression of ALC-1 improves the contractile state of the adult human heart. We propose that two evolutionarily divergent compensatory mechanisms for increased work demand exist in the mammalian heart: MHC regulation in rodents and essential MLC regulation, of cardiac contractility, in humans. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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