Ionic mechanisms for spontaneously beating in monkey sino-atrial nodal cells

用兔、豚鼠和大鼠研究了窦房结细胞自律化的机制。然而，由于实验技术的困难和经济上的支持，大多数与人类相似的猴窦房结细胞从未被检测过。经过多次反复试验，我们已经建立了一种分离猴窦房结细胞的技术。进行了全细胞膜片钳实验和电流钳实验。我们发现，自发搏动的猴窦房结细胞启动的离子机制与其他物种不同。在猴窦房结细胞中，超极化激活的内向电流(If)即使在强脉冲时也不明显被激活。阐明猴窦房结自发搏动的离子机制，对临床治疗和预防心律失常、心力衰竭、猝死等心脏疾病具有重要意义。

The mechanism for automaticity of sino-atrial nodal cells has been investigated using rabbit, guinea pig and rat. However, monkey sino-atrial nodal cells mostly resemble to human being have never been examined, because of difficult experimental techniques and economical supports. We have already established a technique for an isolation of sino-atrila nodal cells of monkey by many repeated trials. Whole-cell and current clamp patch-clamp experiments were carried out. We found that the Ionic mechanisms for the initiation of spontaneously beating monkey sino-atrial nodal cells are different from other species. In monkey sino-atrial nodal cells, the hyper polarization-activated inward current (I_f) was not markedly activated even at strong pulses. This means that the I_f current may be not always contributed to the normal spontaneously beating.To elucidate the ionic mechanisms for the automaticity in monkey sino-atrial nodal eelIs plays an important role for clinically treatment and prevention of heart diseases such as arrhythmias, cardiac failure and sudden death.