心肌单细胞兴奋模式转迁规律和转迁过程中延迟后去极化、早后去极化的生成

实验观察了培养心肌单细胞自发性兴奋节律的不同模式以及兴奋模式的转迁规律。结果表明，单细胞在正常灌流条件下可处于不同的兴奋状态，产生不同的兴奋节律，包括延迟后去极化、早后去极化现象。不同的兴奋模式在膜电流改变条件下可规律地相互转迁。随外向电流的逐渐减弱、内向电流的逐渐加强，同一细胞顺序历经“极化”静息状态、含延迟后去极化电位的节律、连续兴奋节律、含早后去极化电位的节律和“去极化”静息状态的兴奋节律动态转迁过程，形成心肌单细胞自发兴奋的哗律谱系”。其中延迟后去极化节律介于“极化”静息状态和连续放电节律之间，是连续放电节律向“极化”静息过渡的一种表现形式。而早后去极化节律则介于连续放电节律和“去极化”静息状态之间，是连续放电向“去极化”静息过渡的一种表现形式。哗律谱系”的概念在延迟后去极化、早后去极化现象和正常节律之间建立了内在联系。

The exciting activity transition rule of single cardiac myocytes and the generation of delayed after-depolarization and early after-depolarization during transition process

Several exciting activity patterns, together with delayed after-depolarization (DAD) and early after-depolarization (EAD), were observed in cultured Neonatal rat's single cardiac myocytes in normal Tyrode solutions by using whole cell current clamp. These different patterns could transit among each other during an inward or outward current injection. With the outward current decreased and the inward current increased gradually, the cell showed a clearly transition process, from the resting state of polarization to the DAD rhythm, the uninterrupted exciting rhythm, the EAD rhythm, finally to the resting state of over-depolarization, which formed a “spectrum of rhythms”. The DAD rhythm was located between the resting state of polarization and the uninterrupted exciting rhythm, and the EAD rhythm located between the uninterrupted exciting rhythm and the resting state of over-depolarization in this “spectrum of rhythms”. The "spectrum of rhythms" established a deep relationship between normal and abnormal cardiac rhythms.