Cerutti C, Barres C, Paultre C
Faculty of Pharmacy, Department of Physiology and Clinical Pharmacology, Centre National de la Recherche Scientifique, Lyon, France.
Am J Physiol. 1994 May;266(5 Pt 2):H1993-2000. doi: 10.1152/ajpheart.1994.266.5.H1993.
The role of the baroreflex in the spectral characteristics of mean arterial pressure (MAP) and heart rate (HR) was investigated in 12 control rats and 9 rats with chronic sinoaortic baroreceptor denervation (SAD) during 1) basal conditions and 2) ganglionic blockade with chlorisondamine and restoration of the basal MAP level. In SAD rats, power spectral density of MAP, estimated by a fast Fourier transform, was reduced in the low-frequency (LF, 0.27- to 0.74-Hz) band. Ganglionic blockade highly decreased LF power spectral density of MAP in control rats. No relationship was found between the MAP response to chlorisondamine, taken as an index of the sympathetic vasomotor tone, and the basal LF power spectral density. Transfer function analysis between MAP and HR showed that, in control rats, coherence was high for frequencies surrounding the LF and high-frequency peaks. In SAD rats, coherence was abolished in the LF band but maintained in the high-frequency band. In conclusion, approximately 80% of the LF power spectral density of MAP depends on the sympathetic nervous system activity, and the baroreflex accounts for one-half of this power and for the coherence between MAP and HR oscillations in the LF band.
在12只对照大鼠和9只慢性窦主动脉压力感受器去神经支配（SAD）大鼠中，研究了压力反射在平均动脉压（MAP）和心率（HR）频谱特性中的作用，实验分两个阶段进行：1）基础状态；2）用氯异吲哚铵进行神经节阻断并恢复基础MAP水平。在SAD大鼠中，通过快速傅里叶变换估计的MAP功率谱密度在低频（LF，0.27至0.74赫兹）频段降低。神经节阻断使对照大鼠MAP的LF功率谱密度大幅降低。以氯异吲哚铵的MAP反应作为交感血管运动张力指标，未发现其与基础LF功率谱密度之间存在关联。MAP与HR之间的传递函数分析表明，在对照大鼠中，围绕LF和高频峰值的频率处相干性较高。在SAD大鼠中，LF频段的相干性消失，但高频频段的相干性得以维持。总之，MAP的LF功率谱密度约80%取决于交感神经系统活动，压力反射占该功率的一半，并负责LF频段中MAP与HR振荡之间的相干性。
