清醒大鼠的心血管自主功能：一种促进稳定状态的新方法。
Cardiovascular autonomic function in conscious rats: a novel approach to facilitate stationary conditions.
作者信息
Ramaekers Dirk, Beckers Frank, Demeulemeester Hilde, Aubert André E
机构信息
Dept. of Cardiology, University Hospital Gasthuisberg O-N, Herestraat 49, B-3000 Leuven, Belgium.
出版信息
Ann Noninvasive Electrocardiol. 2002 Oct;7(4):307-18. doi: 10.1111/j.1542-474x.2002.tb00179.x.
BACKGROUND
An experimental setting and software were developed to evaluate cardiovascular autonomic function in conscious rats. A restrained approach was used, which, upon proper habituation, induced little or no stress in the rats and limited motion artifacts.
METHODS
The ECG and arterial blood pressure were recorded. Time- and frequency-domain indices of heart rate variability (HRV) and blood pressure variability (BPV) were calculated. The spontaneous baroreflex sensitivity (spBRS) was estimated using the method of statistical dependence.
RESULTS
The power spectra clearly concentrated in a frequency band with center frequency around 0.4 Hz, the low frequency (LF) component, and one at the respiratory frequency at 1.5 Hz, the high frequency (HF) component. In baseline conditions, a direct association existed between mean R-R and especially HRV parameters denoting vagal modulation such as rMSSD, pNN5, and HF power. Beta-adrenergic blockade by propranolol diminished basal heart rate. Vagal indices increased while there was an exclusive decrease in the low frequency band of HRV. Alpha-adrenergic blockade with phentolamine produced a depressor response with tachycardia, and a clear decrease in the LF component of BPV. Both the LF and HF component in the HRV spectrum were virtually absent. Cholinergic blockade with atropine did not significantly alter BP but induced a clear tachycardia with decreased vagal indices. The HF component of HRV was completely abolished and the LF band was reduced.
CONCLUSIONS
Both alpha- and beta-adrenergic blockade left spBRS virtually unaltered, while cholinergic blockade profoundly diminished spBRS. Spectral fluctuations of beta-sympathetic tone were restricted to the LF range of HRV, while the HF respiratory component represented vagal modulation. The alpha-sympathetic system played a dominant role in the LF oscillations of BPV. A role of the vagus in the HF oscillations of BPV in the rat is questioned. The baroreflex depended mainly on changes in vagal activity.
背景
开发了一种实验装置和软件来评估清醒大鼠的心血管自主神经功能。采用了一种约束方法，经过适当的适应过程后，该方法在大鼠中引起的应激很小或没有应激，并限制了运动伪影。
方法
记录心电图和动脉血压。计算心率变异性（HRV）和血压变异性（BPV）的时域和频域指标。使用统计依赖性方法估计自发压力反射敏感性（spBRS）。
结果
功率谱明显集中在中心频率约为0.4Hz的频带，即低频（LF）分量，以及呼吸频率为1.5Hz的高频（HF）分量。在基线条件下，平均R-R与特别是表示迷走神经调制的HRV参数（如rMSSD、pNN5和HF功率）之间存在直接关联。普萘洛尔对β-肾上腺素能的阻断降低了基础心率。迷走神经指标增加，而HRV的低频带出现唯一的下降。酚妥拉明对α-肾上腺素能的阻断产生了伴有心动过速的降压反应，并且BPV的LF分量明显下降。HRV谱中的LF和HF分量几乎都不存在。阿托品对胆碱能的阻断没有显著改变血压，但引起明显的心动过速，迷走神经指标降低。HRV的HF分量完全消失，LF带减少。
结论
α-和β-肾上腺素能阻断均使spBRS基本保持不变，而胆碱能阻断则显著降低spBRS。β-交感神经张力的频谱波动局限于HRV的LF范围，而HF呼吸分量代表迷走神经调制。α-交感神经系统在BPV的LF振荡中起主导作用。迷走神经在大鼠BPV的HF振荡中的作用受到质疑。压力反射主要取决于迷走神经活动的变化。
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