Hirota A, Kamino K, Komuro H, Sakai T, Yada T
J Physiol. 1985 Dec;369:209-27. doi: 10.1113/jphysiol.1985.sp015897.
Spontaneous action potential and contraction in the early embryonic heart of the rat have been monitored optically using a voltage-sensitive merocyanine-rhodanine dye together with a multiple-element photodiode matrix array, and the onset of rhythmical action-potential activity in the early phases of rat cardiogenesis was conclusively determined for the first time. Spontaneous rhythmical action potentials were first generated in the central part of the embryonic heart at the middle period of the 3-somite stage of development, at 91/2 days after copulation. Subsequently, contractions coupled with the action potential also appeared at the end of the 3-somite stage. Usually, at the 3-somite stage, spontaneous action signals were synchronized among the different areas in the heart. From this result, it is evident that the paired right and left cardiac primordia are fused completely at the time of initiation of spontaneous electrical activity. In the 3-somite embryonic heart, excitatory waves were conducted radially over the heart, at a uniform rate (0.4-0.8 mm/s), from the pace-making area. However, the regional priority of pace-making activity is not rigid but is flexible.
利用电压敏感染料部花青罗丹宁和多元光电二极管矩阵阵列，对大鼠早期胚胎心脏的自发动作电位和收缩进行了光学监测，首次确凿地确定了大鼠心脏发生早期节律性动作电位活动的起始时间。自发节律性动作电位首先在胚胎心脏的中央部分产生，发育至3体节期中期，即交配后9.5天。随后，与动作电位相关的收缩也出现在3体节期末期。通常，在3体节期，心脏不同区域的自发动作信号是同步的。由此结果可见，左右成对的心脏原基在自发电活动开始时已完全融合。在3体节期胚胎心脏中，兴奋波以均匀速率（0.4 - 0.8毫米/秒）从起搏区域沿径向传导至整个心脏。然而，起搏活动的区域优先性并非固定不变，而是具有灵活性。
