Alipov N N, Sergeeva O V, Kuznetsova T E, Bobrova N A, Abdulkerimova N Z
Department of Normal Physiology, Russian State Medical University, Moscow.
Bull Exp Biol Med. 2005 Nov;140(5):477-82. doi: 10.1007/s10517-006-0001-y.
The effects of atropine and beta-adrenoceptor blockers on mean HR, wave structure of the cardiac rhythm, and chronotropic reaction to noise stress were examined in cats. Atropine (0.5 mg/kg) increased the mean HR and significantly decreased the spectrum power of HF, LF, and VLF oscillations. The decrease in HF power was most pronounced, which enhanced LF/HF ratio. Propranolol (0.5 mg/kg) decreased the mean HR and slightly increased the power of HF, LF, and VLF oscillations. Atenolol (2 mg/kg) exerted similar but more pronounced effects. beta-Adrenoceptor blockers increased HF power to a greater extent than LF and VLF power, which led to a decrease in LF/HF ratio. Atropine markedly decreased the chronotropic reaction to stress. beta-Adrenoceptor blockers produced no effect on the amplitude of this reaction, but accelerated restoration of initial HR. It is established that the changes in power spectrum of HR and the phase reflex reactions in cats are mediated by parasympathetic influences; the sympathetic system is involved only in the control of mean HR, probably in response to the level of animal activity. The changes in LF/HF ratio during blockade of sympathetic and parasympathetic systems are caused by opposite influences of these systems on HF oscillations, but not by hypothetic "sympathetic" and "parasympathetic" nature of LF and HF oscillations of the heart rhythm.
在猫身上研究了阿托品和β-肾上腺素能受体阻滞剂对平均心率、心律的波形结构以及对噪声应激的变时反应的影响。阿托品（0.5mg/kg）可提高平均心率，并显著降低高频（HF）、低频（LF）和极低频（VLF）振荡的频谱功率。HF功率的降低最为明显，这提高了LF/HF比值。普萘洛尔（0.5mg/kg）可降低平均心率，并略微增加HF、LF和VLF振荡的功率。阿替洛尔（2mg/kg）产生了类似但更明显的效果。β-肾上腺素能受体阻滞剂使HF功率增加的程度大于LF和VLF功率，这导致LF/HF比值降低。阿托品显著降低了对应激的变时反应。β-肾上腺素能受体阻滞剂对该反应的幅度没有影响，但加速了初始心率的恢复。已证实，猫心率功率谱的变化和相位反射反应是由副交感神经影响介导的；交感神经系统仅参与平均心率的控制，可能是对动物活动水平的反应。交感神经和副交感神经系统阻断期间LF/HF比值的变化是由这些系统对HF振荡的相反影响引起的，而不是由心律的LF和HF振荡的假设“交感神经”和“副交感神经”性质引起的。
