Optical imaging analysis of the functional organization of the receptor-intracellular signal transduction system in the early embryonic heart.

电压敏感染料相关吸收信号为监测早期胚胎心脏自发电活动提供了一种新的方法。我们采用快速部花青-若丹宁电压敏感染料（NK 2761）和多元件（16 × 16）光电二极管阵列，在鸡胚心脏第一次肌肉收缩出现的阶段，采用多位点光学记录跨膜电压活动，监测鸡胚心脏的动作电位。应用肾上腺素，心脏起搏器的节律变得更快，尽管这种药物的作用与成人心脏相比很弱。另一方面，咖啡因的应用加快了起搏器的节律，表明细胞内信号转导系统部分发挥作用。然而，肾上腺素的应用减慢了起搏器兴奋波的传导速度。这些结果表明，在早期胚胎心脏，细胞内的信号转导系统是有些不同的成人心脏。

Voltage-sensitive dye-related absorption signals have provided a new method for monitoring spontaneous electrical activity in the early embryonic heart. We have introduced multiple-site optical recording of transmembrane voltage activity, using a fast merocyanine-rhodanine voltage-sensitive dye (NK2761) and a multi-element (16 X 16) photodiode array, to monitor action potentials in the early embryonic chick hearts at the stages when the first muscle contractions appear. By the application of adrenaline, the rhythm of the cardiac pacemaker became faster although the effect of this drug was very weak in comparison with that in adult hearts. On the other hand, the application of caffeine accelerated the rhythm of the pacemaker, suggesting that the intracellular signal transduction system was partially functioning. However, the application of adrenaline slowed the conduction velocity of the excitatory wave from the pacemaker. These results suggest that, in the early embryonic heart, the intracellular signal transduction system is somewhat different from that of adult hearts.