White C W
Am J Physiol. 1981 May;240(5):H793-9. doi: 10.1152/ajpheart.1981.240.5.H793.
The mechanism of the attenuated arterial baroreceptor control of heart rate in heart failure was studied in 18 unanesthetized dogs after the development of chronic right-heart failure and compared to 12 control animals. The change in heart rate and arterial pressure in response to increases in right carotid sinus pressure during isolated carotid sinus perfusion was markedly reduced in heart failure (P less than 0.05). After vagotomy the difference in heart rate responses persisted, but was less pronounced (P = 0.065). The chronotropic response to perfusion of the sinus node artery with acetylcholine in heart-failure dogs showed a selectively depressed response, when compared to norepinephrine and hypertonic saline. The ratio of the change in heart rate in heart-failure vs. control dogs was 57% for acetylcholine but was not diminished for hypertonic saline (114%). The effect of direct vagal nerve stimulation on changes in heart rate was also markedly reduced in heart-failure dogs. These studies demonstrate that the alterations in baroreceptor control of heart rate in heart failure involve both the parasympathetic and sympathetic baroreflex efferent limbs. There is, in addition, a depressed responsiveness of the sinus node to cholinergic stimuli.
在18只未麻醉的犬身上研究了心力衰竭时动脉压力感受器对心率控制减弱的机制，这些犬已发展为慢性右心衰竭，并与12只对照动物进行比较。在孤立的颈动脉窦灌注期间，心力衰竭时对右颈动脉窦压力升高的心率和动脉压变化明显降低（P<0.05）。迷走神经切断术后，心率反应的差异仍然存在，但不太明显（P = 0.065）。与去甲肾上腺素和高渗盐水相比，心力衰竭犬对窦房结动脉灌注乙酰胆碱的变时反应表现出选择性抑制反应。心力衰竭犬与对照犬的心率变化比值，乙酰胆碱为57%，但高渗盐水未降低（114%）。直接迷走神经刺激对心力衰竭犬心率变化的影响也明显降低。这些研究表明，心力衰竭时压力感受器对心率控制的改变涉及副交感神经和交感神经压力反射传出支。此外，窦房结对胆碱能刺激的反应性降低。
