环磷酸腺苷（cAMP）的积累增强了心率的动态迷走神经控制。
Accumulation of cAMP augments dynamic vagal control of heart rate.
作者信息
Nakahara T, Kawada T, Sugimachi M, Miyano H, Sato T, Shishido T, Yoshimura R, Miyashita H, Inagaki M, Alexander J, Sunagawa K
机构信息
Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, Suita, Osaka 565, Japan.
出版信息
Am J Physiol. 1998 Aug;275(2):H562-7. doi: 10.1152/ajpheart.1998.275.2.H562.
Recent investigations in our laboratory using a Gaussian white noise perturbation technique have shown that simultaneous sympathetic stimulation augmented the gain of the transfer function from vagal stimulation frequency to heart rate response. However, the mechanism of that augmentation remains to be elucidated. In this study, we examined in anesthetized rabbits how three pharmacological interventions known to cause intracellular accumulation of cAMP affected the transfer function. Isoproterenol (0.3 microg . kg-1 . min-1 iv) increased the dynamic gain of transfer function from 7.12 +/- 0.67 to 12.4 +/- 1.21 beats . min-1 . Hz-1 (P < 0.05) without changing the corner frequency or the lag time. Similar augmentations were observed when forskolin (5 microg . kg-1 . min-1 iv) or theophylline (20 mg/kg iv) was administered under conditions of beta-adrenergic blockade. These results suggest that the accumulation of cAMP at postjunctional effector sites contributes, at least in part, to the sympathetic augmentation of the dynamic vagal control of heart rate.
我们实验室最近采用高斯白噪声扰动技术进行的研究表明，同时进行交感神经刺激可增强从迷走神经刺激频率到心率反应的传递函数增益。然而，这种增强的机制仍有待阐明。在本研究中，我们在麻醉兔中研究了三种已知会导致细胞内cAMP积累的药理学干预措施如何影响传递函数。异丙肾上腺素（0.3μg·kg-1·min-1静脉注射）使传递函数的动态增益从7.12±0.67增加到12.4±1.21次·min-1·Hz-1（P < 0.05），而不改变转折频率或延迟时间。在β-肾上腺素能阻断条件下给予福斯高林（5μg·kg-1·min-1静脉注射）或茶碱（20mg/kg静脉注射）时，观察到类似的增强。这些结果表明，接头后效应位点处cAMP的积累至少部分地促成了交感神经对心率动态迷走神经控制的增强。
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