How does adrenaline accelerate the heart?
HF Brown, D DiFrancesco, SJ Noble - Nature, 1979 - nature.com
HF Brown, D DiFrancesco, SJ Noble
Nature, 1979•nature.comTHE 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 …
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 …
Abstract
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.
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