| Autor: |
Naumann, Anne, Neubauer, Stefan, Kuhlencordt, Peter, Kai Hu, Rong Tian, Gaudron, Peter, Ertl, Georg |
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| Zdroj: |
Basic Research in Cardiology; Mar2005, Vol. 100 Issue 2, p171-178, 8p |
| Abstrakt: |
Changes in creatine kinase (CK) and lactate dehydrogenase (LDH) isoform expression occur in residual tissue after myocardial infarction. It is unknown how these changes correlate with cardiac remodeling, contractile performance and efficiency. Rats were subjected to left coronary artery ligation (MI) or sham operation (sham). Left ventricular end-diastolic pressure (EDP) was measuredin vivo8 weeks later. Hearts were isolated, buffer-perfused (Langendorff) at constant pressure and isovolumetric left ventricular (LV) pressure-volume (PV) curves were recorded. LV PV areas (PVA) were calculated and related to oxygen consumption. Biopsies of intact left ventricular tissue were taken for biochemical measurements. Correlations betweenin vivoEDP and biochemical parameters were found: Total CK activity (r = -.47, p = .022), CK isoenzyme percentage for BB (r = +.57, p = .004), MB (r = +.54, p = .006) and CK-mito (r = -.51, p = .012), total creatine content (r = -.61, p = .002) and the ratio of LDH5/LDH1 (r = .49, p = .016). Correlations were also detected for left ventricular volume and PVAs atin vivoEDP demonstrating that the extent of CK and LDH system alterations correlate with the extent of LV dilatation and mechanical energy requirements. The slope of the MVO2-PVA relation decreased significantly with increasing values ofin vivoEDP (r = -.68, p = 0.0003) indicating increased contractile ef.ciency. Improved efficiency correlated with the increase in fetal CK isoenzyme expression. Thus, contractile efficiency increases parallel to the extent of left ventricular dilatation and dysfunction. CK and LDH system changes in residual intact myocardium also occur proportional to LV dysfunction. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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