Dorward P K, Riedel W, Burke S L, Gipps J, Korner P I
Circ Res. 1985 Oct;57(4):618-33. doi: 10.1161/01.res.57.4.618.
Curves relating renal sympathetic nerve activity and mean arterial pressure were derived in conscious rabbits during ramp changes in mean arterial pressure, elicited by perivascular balloon inflation. The renal sympathetic nerve activity-mean arterial pressure relationship consisted of a high-gain sigmoidal region about resting, where renal sympathetic nerve activity rose or fell in response to moderate falls and rises of mean arterial pressure. With larger pressure rises, renal sympathetic nerve activity first fell to a lower plateau and then reversed at even higher mean arterial pressure. When mean arterial pressure was lowered below resting, renal sympathetic nerve activity rose to an upper plateau and then reversed abruptly toward resting at low mean arterial pressure. Both arterial and cardiac baroreceptors exerted substantial inhibitory influences on renal sympathetic nerve activity at all pressure levels. These effects appeared additive over the central high gain region of the curve, but beyond this region there were non-additive interactions. The latter were affected considerably by alfathesin anesthesia. In other experiments, we studied the effects of sustained alterations in resting mean arterial pressure induced by infusing nitroprusside and phenylephrine, which produced rapid resetting of the renal baroreflex. The latter could be accounted for, in part, by resetting of the threshold of the arterial baroreceptors and in part by contributions from other afferents, probably the cardiac receptors. During resetting associated with nitroprusside-induced falls in resting blood pressure, high-gain reflex adjustments in renal sympathetic nerve activity to moderate changes in mean arterial pressure were preserved, but during resetting associated with phenylephrine-induced rises in resting mean mean arterial pressure, the resting renal sympathetic nerve activity lay on the lower curve plateau, resulting in reduction in the apparent gain of the reflex renal sympathetic nerve activity response to moderate changes in mean arterial pressure.
通过血管周围气囊充气引起平均动脉压呈斜坡式变化，从而得出清醒家兔肾交感神经活动与平均动脉压的关系曲线。肾交感神经活动-平均动脉压关系包括一个围绕静息值的高增益S形区域，在此区域，肾交感神经活动会随着平均动脉压的适度下降和上升而升高或降低。随着压力进一步升高，肾交感神经活动首先降至较低平台期，然后在更高的平均动脉压时反转。当平均动脉压降至静息值以下时，肾交感神经活动升至较高平台期，然后在低平均动脉压时突然反转至静息状态。在所有压力水平下，动脉压力感受器和心脏压力感受器均对肾交感神经活动施加显著的抑制作用。这些作用在曲线的中央高增益区域似乎具有叠加性，但在该区域之外则存在非叠加性相互作用。后者受阿法沙辛麻醉的影响很大。在其他实验中，我们研究了输注硝普钠和去氧肾上腺素引起的静息平均动脉压持续改变的影响，这导致肾压力反射的快速重置。后者部分可归因于动脉压力感受器阈值的重置，部分可归因于其他传入神经（可能是心脏感受器）的作用。在与硝普钠引起的静息血压下降相关的重置过程中，肾交感神经活动对平均动脉压适度变化的高增益反射调节得以保留，但在与去氧肾上腺素引起的静息平均动脉压升高相关的重置过程中，静息肾交感神经活动处于较低的曲线平台期，导致反射性肾交感神经活动对平均动脉压适度变化的反应的表观增益降低。
