Korean J Intern Med.  2000 Jan;15(1):56-64.

Apoptosis in dilated cardiomyopathy

• Hong BK
• Kwon HM
• Byun KH
• Kim D
• Choi EY
• Kang TS
• Kang SM
• Chun KJ
• Jang Y
• Kim HS

Abstract

OBJECTIVE
Cardiomyopathy, a popular diagnosis that always obscures more than it reveals, nevertheless has several characteristic histological features. These prominently include widespread focal myocardial fibrosis and associated hypertrophy of surviving cardiac myocyte. In fact, focal noninflammatory degeneration (not necrosis) has been demonstrated as a feature of many forms of cardiac hypertrophy. We hypothesized that this loss of myocardial cells in dilated cardiomyopathy (DCMP) may result from cell death by apoptosis. METHODS: Endomyocardial biopsy specimens from the right ventricles of six patients who suffered from DCMP were studied, and myocardial specimens from two persons who died in motor vehicle accidents were used as negative controls. For identification of apoptosis, immunohistochemistry with terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling was performed. In addition, apoptosis was confirmed morphologically by confocal laser scanning microscopy with propidium iodide. RESULTS: Apoptosis, that was represented by an apoptotic index ranging from 19.8 to 25.4+ACU-, could be extensively seen in myocytes and also rarely in non-myocytes of interstitium and vascular endothelium. Morphologically, there were a lot of nuclei with clumps of condensed chromatin, suggestive of apoptosis. CONCLUSION: The present study demonstrated that myocyte loss in DCMP might be mainly due to the apoptosis of myocytes and interstitial cells, rather than inflammation or cell necrosis.

Keyword

Dilated cardiomyopathy; apoptosis; terminal deoxynucleotidyl transferase nick end-labeling; confocal laser scanning microscopy

MeSH Terms

Adult
Analysis of Variance
Apoptosis/physiology+ACo-
Biopsy, Needle
Cardiomyopathy, Congestive/physiopathology
Cardiomyopathy, Congestive/pathology+ACo-
Caspases/analysis
Enzyme Precursors/analysis
Female
Human
Immunohistochemistry
In Situ Nick-End Labeling
Male
Microscopy, Confocal
Middle Age
Myocardium/pathology+ACo-
Reference Values
Statistics, Nonparametric