Automaticity, triggered activity, and responses to adrenergic stimulation in cat subendocardial Purkinje fibers after healing of myocardial infarction.
Automaticity, triggered activity, and responses to adrenergic stimulation in cat subendocardial Purkinje fibers after healing of myocardial infarction.
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心肌梗死愈合后猫心内膜下浦肯野纤维的自动性、触发活动和对肾上腺素能刺激的反应。
DOI：
10.1161/01.cir.75.3.651
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发表时间：
1987
期刊：
影响因子：
37.8
通讯作者：
Myerburg,RJ
中科院分区：
文献类型：
--
作者：
Kimura,S;Bassett,AL;Kohya,T;Kozlovskis,PL;Myerburg,RJ
我们研究了猫左心室愈合的梗死疤痕（梗死准备）和远端正常区（非梗死准备）上的心内膜下浦肯野纤维的自动性、触发活性以及对α和β肾上腺素能刺激的反应。在结扎左前降支和旋支的多根远端支后2至4个月对这些制剂进行研究。来自正常心脏相应区域的心内膜下浦肯野纤维作为对照样本（对照制剂）。跨膜动作电位特征和自动性（自发第4期去极化）在对照、非梗死和梗死制剂中没有差异。然而，在周期长度小于400毫秒的情况下，与对照组和非梗死制剂相比，在更大程度上抑制了梗死制剂浦肯野纤维的自动机。异丙肾上腺素(10（-10)M至10(-6)M）灌注期间自动速率的变化在三组制剂之间没有差异，但暴露于苯肾上腺素(10（-9)M至10(-5)M）存在5 × 10(-7)M心得安的情况下，比对照组或非梗死制剂更大程度地降低了浦肯野纤维的自动速率。29个梗死制剂中有10个（34%）记录了延迟后去极化引起的触发活动，但在12个对照组和10个非梗死制剂中没有记录。在5 × 10(-7)M心得安存在的情况下，细胞外钙++浓度、10(-7)M异丙肾上腺素和10(-5)M苯肾上腺素的增加会增强这些后电位。我们的结论是，覆盖在愈合的梗死疤痕上的浦肯野纤维改变了自发自动性的生理机能，增强了对α -肾上腺素能干预的反应，并倾向于触发活动，α -和β -肾上腺素能的作用可能通过增强愈合的心肌梗死的后电位而导致心律失常的恶化。
We studied automaticity, triggered activity, and responses to alpha- and beta-adrenergic stimulation in subendocardial Purkinje fibers overlying healed infarct scars (infarct preparation) and from remote normal zones (noninfarct preparation) of cat left ventricles. The preparations were studied 2 to 4 months after ligation of multiple distal tributaries of the left anterior descending and circumflex arteries. Subendocardial Purkinje fibers from corresponding areas of normal hearts served as control samples (control preparation). Transmembrane action potential characteristics and rates of automaticity (spontaneous phase 4 depolarization) did not differ among control, noninfarct, and infarct preparations. However, overdrive at cycle lengths of less than 400 msec suppressed automaticity to a greater degree in Purkinje fibers of infarct preparations than those of control and noninfarct preparations. Changes in automatic rate during superfusion with isoproterenol (10(-10)M to 10(-6)M) were not different among the three groups of preparations, but exposure to phenylephrine (10(-9)M to 10(-5)M) in the presence of 5 X 10(-7)M propranolol reduced the automatic rate to a greater degree in Purkinje fibers of infarct preparations than those of control or noninfarct preparations. Triggered activity arising from delayed afterdepolarizations was recorded in 10 of 29 infarct preparations (34%), but not in 12 control and 10 noninfarct preparations. These afterpotentials were augmented by increasing extracellular Ca++ concentration, 10(-7)M isoproterenol, and 10(-5)M phenylephrine in the presence of 5 X 10(-7)M propranolol. We conclude that Purkinje fibers overlying healed infarct scars have altered physiology of spontaneous automaticity, enhanced responses to alpha-adrenergic interventions, and a tendency to triggered activity, and that both alpha- and beta-adrenergic effects may result in worsening of arrhythmias by augmentation of afterpotentials in healed myocardial infarction.
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影响因子：
20.1
作者：
ROSEN, MR;DANILO, P
通讯作者：
DANILO, P
影响因子：
20.1
作者：
L. Mary;A. Hordof;P. Danilo;J. Malm;M. Rosen
通讯作者：
M. Rosen
24小时实验性心肌梗死中室性心律失常的心内膜下起源
影响因子：
37.8
作者：
L. Horowitz;J. Spear;E. Moore
通讯作者：
E. Moore
在钙水平升高的情况下，通过α-肾上腺素能刺激，延迟后去极化并触发猫浦肯野纤维的活动。
影响因子：
37.8
作者：
Kimura,S;Cameron,JS;Kozlovskis,PL;Bassett,AL;Myerburg,RJ
通讯作者：
Myerburg,RJ
由β-肾上腺素能药物引起的部分去极化心脏浦肯野纤维的传导阻滞。
DOI：
--
发表时间：
1971
期刊：
Nature: New biology
影响因子：
--
作者：
P. Cranefield;B. Hoffman;A. L. Wit
通讯作者：
A. L. Wit