Kawada Toru, Turner Michael J, Shimizu Shuji, Fukumitsu Masafumi, Kamiya Atsunori, Sugimachi Masaru
Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan.
Am J Physiol Regul Integr Comp Physiol. 2017 May 1;312(5):R787-R796. doi: 10.1152/ajpregu.00530.2016. Epub 2017 Mar 8.
Recent clinical trials in patients with drug-resistant hypertension indicate that electrical activation of the carotid sinus baroreflex can reduce arterial pressure (AP) for more than a year. To examine whether the electrical stimulation from one baroreflex system impedes normal short-term AP regulation via another unstimulated baroreflex system, we electrically stimulated the left aortic depressor nerve (ADN) while estimating the dynamic characteristics of the carotid sinus baroreflex in anesthetized normotensive Wistar-Kyoto (WKY; = 8) rats and spontaneously hypertensive rats (SHR; = 7). Isolated carotid sinus regions were perturbed for 20 min using a Gaussian white noise signal with a mean of 120 mmHg for WKY and 160 mmHg for SHR. Tonic ADN stimulation (2 Hz, 10 V, and 0.1-ms pulse width) decreased mean sympathetic nerve activity (73.4 ± 14.0 vs. 51.6 ± 11.3 arbitrary units in WKY, = 0.012; and 248.7 ± 33.9 vs. 181.1 ± 16.6 arbitrary units in SHR, = 0.018) and mean AP (90.8 ± 6.6 vs. 81.2 ± 5.4 mmHg in WKY, = 0.004; and 128.6 ± 9.8 vs. 114.7 ± 10.3 mmHg in SHR, = 0.009). The slope of dynamic gain in the neural arc transfer function from carotid sinus pressure to sympathetic nerve activity was not different between trials with and without the ADN stimulation (12.55 ± 0.93 vs. 13.03 ± 1.28 dB/decade in WKY, = 0.542; and 17.37 ± 1.01 vs. 17.47 ± 1.64 dB/decade in SHR, = 0.946). These results indicate that the tonic ADN stimulation does not significantly modify the dynamic characteristics of the carotid sinus baroreflex.
近期针对耐药性高血压患者的临床试验表明，颈动脉窦压力反射的电激活可使动脉压（AP）降低超过一年。为了研究来自一个压力反射系统的电刺激是否会通过另一个未受刺激的压力反射系统干扰正常的短期动脉压调节，我们在麻醉的正常血压Wistar-Kyoto（WKY；n = 8）大鼠和自发性高血压大鼠（SHR；n = 7）中，在评估颈动脉窦压力反射的动态特性时，对左主动脉减压神经（ADN）进行了电刺激。使用高斯白噪声信号对分离的颈动脉窦区域进行20分钟的扰动，WKY的平均压力为120 mmHg，SHR的平均压力为160 mmHg。持续性ADN刺激（2 Hz、10 V和0.1 ms脉冲宽度）降低了平均交感神经活动（WKY中为73.4±14.0对51.6±11.3任意单位，P = 0.012；SHR中为248.7±33.9对181.1±16.6任意单位，P = 0.018）以及平均动脉压（WKY中为90.8±6.6对81.2±5.4 mmHg，P = 0.004；SHR中为128.6±9.8对114.7±10.3 mmHg，P = 0.009）。在有和没有ADN刺激的试验之间，从颈动脉窦压力到交感神经活动的神经弧传递函数的动态增益斜率没有差异（WKY中为12.55±0.93对13.03±1.28 dB/十倍频程，P = 0.542；SHR中为17.37±1.01对17.47±1.64 dB/十倍频程，P = 0.946）。这些结果表明，持续性ADN刺激不会显著改变颈动脉窦压力反射的动态特性。
