Dissociation of chronotropic and inotropic responses in the rat heart during sympathetic stimulation.
Dissociation of chronotropic and inotropic responses in the rat heart during sympathetic stimulation.
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交感神经刺激期间大鼠心脏变时性和正性肌力反应的分离。
DOI：
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Y. Maruyama
中科院分区：
文献类型：
--
作者：
N. Onuki;H. Takahashi;H. Suzuki;T. Saito;K. Maehara;Y. Maruyama
尚未完全解决变时性和变力性反应如何根据刺激的强度或持续时间而改变，以及在交感神经刺激期间α-血管收缩剂效应如何与代谢性血管舒张竞争。本研究探讨了差频刺激对交感神经刺激时大鼠心脏这些反应的影响，同时保持左心室舒张末期容积恒定。用改良的Krebs-Henseleit溶液以恒定流量或压力灌注心脏。在无或有α或α 2肾上腺素能受体拮抗剂的情况下，在4个频率（0.2、0.5、1和3 Hz）下对去髓大鼠的交感神经（SNS）进行电刺激90 s。在3 Hz SNS期间，心率逐渐增加（30 s时为33+/-10%，90 s时为38+/-14%），而变力作用在约30 s时达到峰值，然后下降（30 s时左心室收缩压为+23+/-8%，90 s时为-1+/-13%）。尽管去甲肾上腺素释放逐渐增加，但这种现象表明负阶梯。收缩力的降低与相同频率的恒定心房起搏所显示的结果没有差异。冠状动脉α 1-血管收缩反应是竞争性的代谢性血管舒张，只有在早期阶段的刺激和α 2-血管收缩作用的冠状动脉循环的调节几乎没有贡献。这些结果与以前的研究结果不同的事实表明，心脏的交感神经调节应该重新考虑，虽然目前的结果直接应用于人类还不清楚，因为物种的差异。
It is not fully resolved how the chronotropic and inotropic responses alter depending on the strength or duration of stimulation, and how the alpha-vasoconstrictor effect competes with metabolic vasodilation during sympathetic stimulation. The present study investigated the effects of differential frequency stimuli on these responses in rat hearts during sympathetic stimulation while keeping the left ventricular end-diastolic volume constant. The heart was perfused at a constant flow or pressure with a modified Krebs-Henseleit solution. Electrical stimulation of sympathetic nerves (SNS) was performed at 4 frequencies (0.2, 0.5, 1 and 3 Hz) for 90 s in pithed rats without or with an a or alpha2 adrenergic receptor antagonist. The heart rate progressively increased during 3-Hz SNS (33+/-10% at 30s, 38+/-14% at 90s), whereas the inotropic action peaked at about 30s and then decreased (left ventricular systolic pressure +23+/-8% at 30s, -1+/-13% at 90s). This phenomenon indicates a negative staircase, in spite of a gradual increase in norepinephrine release. The reduction of contractility did not differ from that shown by constant atrial pacing with an equivalent rate. The coronary alpha1-vasoconstrictor response was competitive with metabolic vasodilation only in the early phase of stimulation and the alpha2-vasoconstrictor action had little contribution to the regulation of coronary circulation. The fact that these results differ from previous findings suggests that sympathetic regulation of the heart should be reconsidered, although direct application of the present results to humans is not clear because of species differences.
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清醒狗中由α1-和α2-肾上腺素受体介导的冠状血管收缩。
DOI：
10.1152/ajpheart.1987.253.2.h388
发表时间：
1987
期刊：
The American journal of physiology
影响因子：
--
作者：
Woodman,OL;Vatner,SF
通讯作者：
Vatner,SF
离体大鼠心脏中阿片肽和肾上腺素能受体信号传导之间的“串扰”。
影响因子：
37.8
作者：
Pepe,S;Xiao,RP;Hohl,C;Altschuld,R;Lakatta,EG
通讯作者：
Lakatta,EG
清醒狗冠状动脉循环的α-肾上腺素调节。
DOI：
10.1016/0002-9149(83)90172-8
发表时间：
1983
期刊：
The American journal of cardiology
影响因子：
--
作者：
Vatner,SF
通讯作者：
Vatner,SF
DOI：
10.1111/j.1432-1033.1989.tb14637.x
发表时间：
1989-03-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
BUNGER, R;MALLET, RT;HARTMAN, DA
通讯作者：
HARTMAN, DA