Tao L, Wang H X, Rao M R
Department of Cardiovascular Pharmacology, Nanjing Medical University.
Yao Xue Xue Bao. 1995;30(5):326-30.
Angiotensin (Ang) II (1, 10, 100 and 1000 nmol.L-1) was found to increase spontaneous contractile frequency dose-dependently in neonatal rat cardiac myocytes cultured for 3 d. After exposure to Ang II (100 nmol.L-1) for 7 d, neonatal rat heart cells became hypertrophy with increased frequency, elevated APA, prolonged ADP50 and ADP90, and shortened SCL. Addition of ouabian (Oua) 50 nmol.L-1 to the hypertrophic myocytes caused more frequent arrhythmia. Taurine (20 mmol.L-1) was shown to inhibit these changes induced by Ang II. These results suggest that Ang II can increase autorhythmicity as well as sensibility to Oua in cultured cardiac myocytes. These effects might be related to the promotion of Ca2+ influx.
研究发现，血管紧张素（Ang）II（1、10、100和1000 nmol·L-1）可使培养3天的新生大鼠心肌细胞的自发收缩频率呈剂量依赖性增加。在暴露于100 nmol·L-1的Ang II 7天后，新生大鼠心脏细胞出现肥大，频率增加，动作电位幅度（APA）升高，动作电位时程50%（ADP50）和动作电位时程90%（ADP90）延长，收缩间期（SCL）缩短。向肥大的心肌细胞中添加50 nmol·L-1的哇巴因（Oua）会导致更频繁的心律失常。结果表明，牛磺酸（20 mmol·L-1）可抑制Ang II诱导的这些变化。这些结果提示，Ang II可增加培养心肌细胞的自律性以及对Oua的敏感性。这些作用可能与促进Ca2+内流有关。
