A COMPARISON OF THE ELECTROPHYSIOLOGIC EFFECTS OF ACUTE AND CHRONIC AMIODARONE ADMINISTRATION ON CANINE PURKINJE-FIBERS
A COMPARISON OF THE ELECTROPHYSIOLOGIC EFFECTS OF ACUTE AND CHRONIC AMIODARONE ADMINISTRATION ON CANINE PURKINJE-FIBERS
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DOI：
10.1097/00005344-198913050-00007
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发表时间：
1989-05-01
影响因子：
3
通讯作者：
GESSMAN, LJ
中科院分区：
文献类型：
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作者：
GALLAGHER, JD;BIANCHI, J;GESSMAN, LJ
采用微电极技术记录细胞内动作电位，评估急性和慢性给药胺碘酮对犬浦肯野纤维的电生理影响。慢性治疗犬接受胺碘酮治疗3周(血清水平0.91 +-。0.09 .mu。G /ml或1.42。10 - 6米)。急性研究使用未经治疗的狗的纤维，用5倍的频率搅拌1小时。10-5 M胺碘酮(32 .mu。g/ml)在Tyrode溶液（KCl = 4 mM）中。急性超熔合使动作电位至50和90%复极的持续时间分别缩短41%和8% (p < 0.01)，并使第0期Vmax由418 +-降低。20到309。23v /s (p < 0.01)（周期长度500ms）。注意到明显的使用依赖性Vmax下降。使用血液交叉灌注技术将未经治疗的狗的纤维急性暴露于长期接受胺碘酮治疗的狗的血液中，使动作电位持续时间减少到50%复极和Vmax，与急性暴露于Tyrode溶液相似。血液交叉灌注用于研究治疗犬与另一只胺碘酮治疗犬的血液混合后的纤维。慢性胺碘酮将动作电位持续时间延长至90%复极的13% (p < 0.02)，与使用未治疗犬的纤维与未治疗犬的血液进行对照研究相比，未改变Vmax。因此，急性过量胺碘酮对犬浦肯野纤维动作电位的影响不同于长期给药胺碘酮的影响。
The electrophysiologic effects of acutely and chronically administered amiodarone on canine Purkinje fibers were assessed using microelectrode techniques to record intracellular action potentials. Chronically treated dogs received amiodarone for 3 weeks (serum levels, 0.91 .+-. 0.09 .mu.g/ml or 1.42 .+-. 10-6 M). Acute studies were performed using fibers from untreated dogs superfused for 1 h with 5 .times. 10-5 M amiodarone (32 .mu.g/ml) in Tyrode''s solution (KCl = 4 mM). Acute superfusion shortened the action potential duration to 50 and 90% repolarization by 41 and 8%, respectively (p < 0.01), and decreased Vmax of phase 0 from 418 .+-. 20 to 309 .+-. 23 V/s (p < 0.01) (paced cycle length of 500 ms). Prominent use-dependent depression of Vmax was noted. Acute exposure of fibers from untreated dogs to blood from dogs chronically treated with amiodarone using the blood cross-perfusion technique decreased the action potential duration to 50% repolarization and Vmax, similar to acute exposure in Tyrode''s solution. Blood cross-perfusion was used to study fibers from treated dogs superfused with blood from another amiodarone-treated dog. Chronic amiodarone prolonged the action potential duration to 90% repolarization by 13% (p < 0.02) and did not change Vmax when compared to control studies using fibers obtained from untreated dogs superfused with blood from untreated dogs. Thus, the effects of acutely superfused amiodarone on action potentials of canine Purkinje fibers differ from the effects of chronically administered amiodarone.