扩张型心肌病的心肌组织细胞凋亡的研究

目的：研究扩张型心肌病（DCM）的心肌细胞凋亡及其与心功能的关系。方法：DCM组21例，其心肌组织14例来自右室心内膜心肌活检（EMB）亚组，7例来自死后尸检（尸检组）；对照组为5例死于非心血管疾病的尸检心肌组织。用原位细胞凋亡检测心肌组织凋亡细胞，计算凋亡指数（AI）。结果（1）DCM组的AI明显高于正常组（P＜0．01），EMB亚组的AI明显低于尸检亚组（P＜0．01，但明显高于对照组（P＜0．01）。（2）DCM组中，心胸比（HTR）＜0．6、左室舒张末期内（LVDd)＜65mm和左室射血分数（LVEF）≥40％的患者AI均分别明显于低于HTR≥0．6、LVDd ≥65mm和LVEF＜40％的患者（P值均＜0．01），但仍分别显著高于对照组（P值均＜0．01）。结论：DCM存在明显心肌细胞凋亡并随心功能恶化而程度加重，提示凋亡是DCM的心肌细胞丢失和心功能不全的重要机制。

Apoptosis of myocardial cells in dilated cardiomyopathy

OBJECTIVE: To study apoptosis of myocardial cells in dilated cardiomyopathy (DCM) and its relation with cardiac function. METHODS: Myocardial samples of 21 patients in a DCM group were obtained from hearts of 14 patients undergoing endomyocardial biopsy (EMB) in right ventricular (EMB sub-group) and from the hearts of the 7 remaining patients at autopsy (Autopsy sub-group). Myocardial samples of a control group were obtained from hearts of 5 patients at autopsy, who died of causes other than cardiovascular disease. Apoptosis was evaluated histochemically by in situ end-labeled DNA (Tunel method). RESULTS: (1) Apoptotic index (AI) of the DCM group was significantly higher than that of the control group(P < 0.01), AI of EMB sub-group was significantly lower than that of autopsy sub-group (P < 0.01), but significantly higher than that of the control group (P < 0.01). (2) AI in patients with heart-thorax ratio (HTR) < 0.6, left ventricular end diastolic diameter (LVDd) < 65 mm and left ventricular ejection fraction (LVEF) > or = 40% was significantly lower than that of patients with HTR > or = 0.6, LVDd > or = 65 mm and LVEF < 40% respectively (P < 0.01 for all), but was significantly higher than that of the control group respectively (P < 0.01 for all). CONCLUSIONS: Apoptotic myocardial cells were frequently observed in the myocardial tissues of the DCM and the magnitude of apoptosis increased with the deterioration of cardiac function, indicating that apoptosis may be an important mechanism of loss of myocardial cells and cardiac dysfunction in the DCM.