EFFECT OF ELECTROTONIC POTENTIALS ON PACEMAKER ACTIVITY OF CANINE PURKINJE-FIBERS IN RELATION TO PARASYSTOLE
EFFECT OF ELECTROTONIC POTENTIALS ON PACEMAKER ACTIVITY OF CANINE PURKINJE-FIBERS IN RELATION TO PARASYSTOLE
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DOI：
10.1161/01.res.39.6.801
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发表时间：
1976-01-01
影响因子：
20.1
通讯作者：
MOE, GK
中科院分区：
文献类型：
--
作者：
JALIFE, J;MOE, GK
将从狗心脏切除的分离的假腱固定在3室组织浴中。在中央室中灌注等渗蔗糖溶液，以在室1和3中的纤维段之间提供电导率降低的区域，室1和3用Tyrode溶液灌注。在腔室1起搏器的自发周期的前半部分期间，在腔室3中诱发的自发或驱动反应的电紧张影响延迟了下一次自发放电。在自发循环的下半部分，当3号灭菌舱段击发时，该效应变为加速。亚阈值去极化电流脉冲50-300毫秒施加在整个蔗糖间隙引起类似程度的延迟或加速。超极化电流引起相反的模式。并行收缩病灶的放电模式可被周围组织活动的电紧张性影响所改变。这些研究结果的意义被认为是有关的机制生产的parasystolic节奏。
Isolated false tendons excised from dog hearts were mounted in a 3-chamber tissue bath. Isotonic sucrose solution was perfused in the central chamber to provide a region of depressed conductivity between the fiber segments in chambers 1 and 3, which were perfused with Tyrode''s solution. The electrotonic influence of spontaneous or driven responses evoked in chamber 3 during the 1st half of the spontaneous cycle of a chamber 1 pacemaker delayed the next spontaneous discharge. This effect changed to acceleration when the chamber 3 segment fired during the 2nd half of the spontaneous cycle. Subthreshold depolarizing current pulses 50-300 ms applied across the sucrose gap caused similar degrees of delay or acceleration. Hyperpolarizing currents caused the reverse pattern. The discharge pattern of a parasystolic focus may be altered by the electrotonic influence of activity in the surrounding tissue. The significance of these findings is considered in relation to the mechanism of production of parasystolic rhythms.