Krieger E M
Heart Institute, University Hospital, Faculty of Medicine, University of São Paulo.
Drugs. 1988;35 Suppl 6:98-103. doi: 10.2165/00003495-198800356-00014.
It is a universally accepted phenomenon that vascular baroreceptors reset to operate at higher pressure levels in hypertension. A rapid or acute resetting can be demonstrated within the first 5 to 15 minutes after arterial pressure has been elevated. However, this resetting is only partial because the increase in pressure threshold for baroreceptor activation represents a fraction (20 to 40%) of the total pressure increase. This acute resetting changes little within the first hours of hypertension. To achieve complete resetting however, that is when the pressure threshold increase equals the total pressure increase, blood pressure needs to be maintained at an elevated level for 48 hours in the rat. Studies of aortic calibre behaviour performed in freely moving rats demonstrated a striking direct relationship between the time taken for the diastolic calibre to reach maximal dilation and the time taken for complete resetting of the aortic baroreceptors. It was also observed that during transient pressure increases the displacement of the diastolic calibre is much greater than the increase in pulsation, indicating that under physiological conditions sustained distension of the diastolic calibre is an important factor in aortic baroreceptor distortion. The data suggest that complete resetting of the baroreceptors in hypertension occurs when the increased stress on the arterial wall is matched by a proportional permanent increase in diastolic calibre.
高血压时血管压力感受器重置为在更高压力水平下运作，这是一个普遍公认的现象。在动脉压升高后的最初5至15分钟内可显示出快速或急性重置。然而，这种重置只是部分的，因为压力感受器激活的压力阈值增加仅占总压力增加的一部分（20%至40%）。在高血压的最初几个小时内，这种急性重置变化很小。然而，要实现完全重置，即压力阈值增加等于总压力增加，在大鼠中需要将血压维持在升高水平48小时。对自由活动大鼠的主动脉管径行为研究表明，舒张期管径达到最大扩张所需时间与主动脉压力感受器完全重置所需时间之间存在显著的直接关系。还观察到，在短暂压力增加期间，舒张期管径的位移远大于搏动增加，这表明在生理条件下，舒张期管径的持续扩张是主动脉压力感受器变形的一个重要因素。数据表明，当动脉壁上增加的应力与舒张期管径成比例的永久性增加相匹配时，高血压中压力感受器会发生完全重置。
