Coote J H, Sato Y
Circ Res. 1977 Jun;40(6):571-7. doi: 10.1161/01.res.40.6.571.
The influence that the pressure-sensitive receptors in the cardiovascular system have on renal nerve activity and on heart rate was compared in normotensive rats (NTR) and spontaneously hypertensive rats (SHR). The cardiovascular receptors were stimulated by raising the blood pressure (BP) with intravenous phenylephrine. The duration of silence in the record of renal sympathetic nerve activity produced by a number of different rises in BP was measured. We found that the pressure that was just able to produce a silence in the nerve activity (threshold pressure) was higher in the SHR (170 mm Hg) than in the NTR (130 mm Hg). Also, comparable rises in BP above the threshold pressure in the SHR and NTR were less effective in the SHR in producing a complete inhibition of sympathetic nerve activity as judged by the short duration of inhibition. In contrast, we found that the changes in heart rate produced by rises in BP above threshold pressure were similar in NTR and SHR although the threshold pressure was somewhat higher in the latter. It was, therefore, concluded that the cardiovascular pressure receptors, apart from being reset to operate at a higher pressure level in the SHR, are less able to inhibit ongoing sympathetic activity than in the NTR. It is suggested that this is most likely due to a high sympathetic activity in the SHR.
在正常血压大鼠（NTR）和自发性高血压大鼠（SHR）中，比较了心血管系统中的压力感受器对肾神经活动和心率的影响。通过静脉注射去氧肾上腺素升高血压（BP）来刺激心血管感受器。测量了由多种不同程度的血压升高所产生的肾交感神经活动记录中的沉默持续时间。我们发现，刚好能够使神经活动产生沉默的压力（阈值压力）在SHR中（170毫米汞柱）高于NTR中（130毫米汞柱）。此外，根据抑制持续时间判断，SHR和NTR中高于阈值压力的可比血压升高在抑制交感神经活动方面对SHR的效果较差。相反，我们发现，高于阈值压力的血压升高所引起的心率变化在NTR和SHR中相似，尽管后者的阈值压力略高。因此，得出的结论是，除了在SHR中被重置为在更高压力水平下运作外，心血管压力感受器抑制正在进行的交感神经活动的能力比NTR中的弱。有人认为，这很可能是由于SHR中交感神经活动较高所致。
