Relationship between age-related changes in functions of endocardial endothelial cells and heart failure

我们从幼龄大鼠（5周龄）和老年大鼠（100周龄）中分离并培养心内膜内皮细胞（EECs），以估计细胞功能与年龄相关的变化。我们还通过将EECs与从猪身上分离的血管内皮细胞（VECs）进行比较，估计了EECs的生理功能。结果1：用胶原酶分离得到EECs，并在涂有大鼠I型胶原的塑料板上传代培养。大鼠脑脊液的融合细胞单层呈典型的鹅卵石样形态。与血管内皮细胞一样，通过摄取DiI-Ac-LDL和存在因子viii相关抗原来测定EECs的纯度始终为95%。2：衰老对大鼠脑电细胞功能的影响。(1)随着年龄的增长，细胞的增殖和迁移有减少的趋势。(2)随着年龄的增长，前列腺素（PGI_2）和一氧化氮（NO）的生成显著降低。暴露于跨壁压力时，幼龄大鼠脑脊液中PGI_2的产生显著增强，而老年大鼠脑脊液中PGI_2的产生无反应。3：与VECs的比较：(1)EECs的细胞生长和抗聚集性能均高于VECs。(2) PGI_2的产生顺序为左心室EECs>右心室EECs>肺动脉ECs>冠状动脉和胸主动脉ECs。(3)跨壁压力增加了EECs的PGI_2产量，降低了NO产量。结论脑电图功能随年龄的增长而衰减，提示脑电图功能障碍参与了老年心力衰竭的增加。由于我们不能在体外仅从大鼠空穴心脏中剥离心内膜，因此本研究未明确脑电图细胞的生理作用。如果我们能建立去除心内膜的方法，其作用将得到显著的阐明。

We isolated and cultured endocardial endothelial cells (EECs) from young (5-week-old) and aged (100-week-old) rats, to estimate age-related changes in the cell functions. We also estimated physiological functions of EECs, by comparison of EECs with the vascular endothelial cells (VECs), which were isolated from pigs.Results1 : EECs were isolated with collargenase and subcultured on plastic plates coated with the rat type I collagen. The confluent cell monolayr of rat EECs exhibited a typical cobblestone-like morphology. The purity of EECs assayd by uptake of DiI-Ac-LDL and the presence of factor VIII-related antigen, was consistently>95%, as for vascular endothelial cells.2 : Effects of aging on functions of rat EECs. (1) Proliferation and migration tended to decrease with aging. (2) Production of prostaxycline (PGI_2) and nitric oxide (NO) in the cells significantly decreased with aging. When exposing to transmural pressure, PGI_2 production of young rat EECs significantly potentiated, but that of aged rat EECs did not response.3 : Comparison with VECs : (1) Cell growth of EECs and the anti-aggregation property were higher than those of VECs. (2) The rank order of PGI_2 production is left ventricle EECs>right ventricle EECs>pulmonary arterial ECs>coronary arterial and thoracic aortic ECs. (3) The transmural pressure increased PGI_2 production and decreased NO production of EECs.ConclusionThe present experiments indicate age-related attenuation of EEC functions and suggest the participation of the dysfunction in increase of heart failure with advancing age. The physiological roles of EECs were not clarified in this study, since we could not denude ex vivo only the endocardium from rat hole heart. If we can establish the method to remove the endocardium, the roles will be remarkably elucidated.