HOW DOES ADRENALINE ACCELERATE THE HEART
HOW DOES ADRENALINE ACCELERATE THE HEART
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DOI：
10.1038/280235a0
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发表时间：
1979-01-01
期刊：
影响因子：
64.8
通讯作者：
NOBLE, SJ
中科院分区：
文献类型：
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作者：
BROWN, HF;DIFRANCESCO, D;NOBLE, SJ
肾上腺素如何作用于窦房结(SA)以加速心率的机制迄今尚不清楚。然而，在心脏的其他部分，肾上腺素增加慢内向(钙/钠)电流1-4，电压记录实验表明，肾上腺素在窦区5-7也有这一作用。在本文报道的电压钳实验中，我们发现肾上腺素确实增加了兔SA结慢内向电流，但它也增加了倾向于减速起搏去极化的外向电流。我们发现，在起搏器去极化发生的电压范围内，一个额外的电流IF被激活：这在正常起搏和肾上腺素诱导的加速中都可能是重要的。
THE way in which adrenaline acts on the sinoatrial (SA) node to accelerate the heart rate has hitherto been obscure. However, in various other parts of the heart adrenaline increases the slow inward (Ca2+/Na+) current1–4, and voltage-recording experiments have indicated that adrenaline also has this action in the sinus region5–7. In the voltage-clamp experiments reported here, we find that adrenaline does indeed increase the slow inward current in the SA node of the rabbit, but that it also augments the outward current which would tend to decelerate pacemaker depolarisation. We find that an additional current,if, is activated within the range of voltage where the pacemaker depolarisation occurs: this could be important both in normal pacemaking and in adrenaline-induced acceleration.