Analysis of Cardiac Collagens in Cardiomyopathic Hamsters, UM-X7.1

Dilated cardiomyopathy (DCM) is characterized with systolic dysfunction and dilatation of both ventricles. By histological examinations, interstitial fibrosis is commonly seen. In this study, cardiac collagens of DCM hamsters (UM-X7. 1) aged 8, 12, 16, 20 and 24 weeks were alalyzed by the colorimetric assay of hydroxyproline and by the densitometric assay of collagens which were separated by SDS-polyacrylamide gel electrophoresis (PAGE). Sex and age matched golden hamsters (GH) were used for control. The hydroxyproline concentration of left ventricles increased during aging in GH (8w 4. 13mg/g, 24w 5.80mg) and DCM (8w 4.88mg, 24w 7.40mg). SDS -PAGE of cardiac collagens of DCM showed no changes of total density of collagens during aging with samples containing same amount of hydroxyproline. In GH, however, the total density collagens decreased during aging. That is: (1) the hydroxyproline concentration of cardiac collagens of GH increased during aging but not the collagen concentration, and (2) the collagen concentration of DCM markedly increased during aging but not the hydroxyproline concentration. This is indicates that the rate of synthesis of cardiac collagens markedly increased during aging in DCM hamsters but not of hyroxylation of cardiac collagens. These results suggest the abnormal increase of unstable cardiac collagens causes to interstitial fibrosis of ventricles. This may result in systolic dysfunction and dilatation of ventricles which are characteristics of DCM.

拡張型心筋症

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