Nilius B, Boldt W, Scheufler K, Herrmann V
Biomed Biochim Acta. 1983;42(2-3):203-13.
The effects of cycle length (CL) alteration on action potentials of isolated trabeculae of the common right atrial working myocardium (M) and isolated preparation of the crista terminalis (CT) of the rabbit heart were studied. Prolonging the CL increased the steady state duration of action potentials in M but decreased it in CT fibres. The repolarization of the post-pause action potentials of the M preparations was characterized by (i) a rapid initial repolarization followed by (ii) a plateau phase and (iii) a retarded terminal repolarization. In CT fibres the retarded repolarization was not observed and the duration of the post-pause action potentials at 90% repolarization is decreased. Premature action potentials of the M preparations were shortened at 90%, but were prolonged at 25% repolarization. Premature action potentials of the CT fibres were prolonged. The post-drive resting transmembrane potential of the M preparations moved to more negative values depending on the CL stimulation. The shift of the post-drive transmembrane resting potential to negative values in CT preparations was preceded by an initial depolarization. The initial depolarization was absent in M preparations. Myofibril-poor pale cells were found consistently in CT, but never in M preparations.
研究了周期长度（CL）改变对兔心脏右心房普通工作心肌（M）分离小梁和终嵴（CT）分离标本动作电位的影响。延长CL增加了M中动作电位的稳态持续时间，但降低了CT纤维中的稳态持续时间。M标本的停搏后动作电位复极化的特征为：（i）快速初始复极化，随后是（ii）平台期和（iii）延迟终末复极化。在CT纤维中未观察到延迟复极化，且90%复极化时停搏后动作电位的持续时间缩短。M标本的过早动作电位在90%复极化时缩短，但在25%复极化时延长。CT纤维的过早动作电位延长。M标本的驱动后静息跨膜电位根据CL刺激向更负值移动。CT标本中驱动后跨膜静息电位向负值的偏移之前有初始去极化。M标本中没有初始去极化。在CT中始终发现肌原纤维少的苍白细胞，但在M标本中从未发现。
