Sequence of excitation as a factor in sympathetic-parasympathetic interactions in the heart.
Sequence of excitation as a factor in sympathetic-parasympathetic interactions in the heart.
复制标题
DOI：
10.1161/01.res.71.4.898
复制
发表时间：
1992-10
影响因子：
20.1
通讯作者：
Tianen Yang;M. N. Levy
中科院分区：
文献类型：
--
作者：
Tianen Yang;M. N. Levy
我们测定了16只开胸麻醉犬交感神经和迷走神经刺激（均为10hz）开始时间的差异对心脏自主神经相互作用的影响。我们总是同时结束交感神经和迷走神经的刺激。单独交感神经刺激1分钟使心率每分钟增加90 +/- 7次（平均+/- SEM），单独迷走神经刺激1分钟使心率每分钟减少67 +/- 5次；也就是说，这些反应的代数和是每分钟增加23次心跳。然而，交感神经和迷走神经联合刺激1分钟实际上使心率每分钟降低35次；也就是说，迷走神经效应占主导地位。当先开始迷走神经刺激时，对联合刺激的变时反应不受前一次迷走神经刺激持续时间的显著影响。然而，当交感神经刺激开始时，随着我们增加前交感神经刺激的持续时间，迷走神经优势（个体反应总和和组合反应之间的差异）逐渐减弱。迷走神经优势从同时刺激时的67 +/- 21次/分下降到前感刺激持续时间为10分钟时的37 +/- 21次/分。交感神经刺激不仅释放去甲肾上腺素，而且释放神经肽Y，这种神经肽抑制迷走神经传递。因此，我们的数据表明，前交感刺激时间越长，迷走神经传递的抑制作用越大（可能是神经肽Y），因此，迷走神经优势就越不明显。
We determined the influence of differences in the time of initiation of sympathetic and vagal stimulation (both at 10 Hz) on the cardiac autonomic interactions in 16 open-chest anesthetized dogs. We always ended the concurrent sympathetic and vagal stimulations simultaneously. Sympathetic stimulation alone for 1 minute increased heart rate by 90 +/- 7 (mean +/- SEM) beats per minute, and vagal stimulation alone for 1 minute decreased heart rate by 67 +/- 5 beats per minute; i.e., the algebraic sum of these responses was an increase of 23 beats per minute. However, combined sympathetic and vagal stimulation for 1 minute actually decreased heart rate by 35 beats per minute; i.e., the vagal effects predominated. When vagal stimulation was initiated first, the chronotropic responses to combined stimulation were not significantly affected by the duration of antecedent vagal stimulation. However, when sympathetic stimulation was initiated first, the vagal predominance (disparity between the summated individual responses and the combined response) progressively diminished as we increased the duration of antecedent sympathetic stimulation. The vagal predominance diminished from a value of 67 +/- 21 beats per minute when the stimulations were initiated simultaneously to a value of 37 +/- 21 beats per minute when the duration of antecedent sympathetic stimulation was 10 minutes. Sympathetic stimulation releases not only norepinephrine but also neuropeptide Y, and this neuropeptide inhibits vagal neurotransmission. Our data suggest, therefore, that the longer the antecedent sympathetic stimulation, the greater the inhibition of vagal neurotransmission (presumably by the neuropeptide Y) and, therefore, the less pronounced the vagal predominance.