Effect of renal perfusion pressure on responses of intrarenal blood flow to renal nerve stimulation in rabbits

被引:10
作者
Guild, SJ
Malpas, SC
Eppel, GA
Nguang, SK
Evans, RG
机构
[1] Univ Auckland, Dept Physiol, Circulatory Control Lab, Auckland, New Zealand
[2] Univ Auckland, Dept Elect & Elect Engn, Auckland, New Zealand
[3] Monash Univ, Dept Physiol, Melbourne, Vic 3168, Australia
关键词
laser Doppler flowmetry; medullary blood flow; pseudorandom binary sequence; renal blood flow; sympathetic nervous system;
D O I
10.1111/j.1440-1681.2004.03947.x
中图分类号
R9 [药学];
学科分类号
1007 ;
摘要
1. We investigated how sympathetic nerve activity and renal perfusion pressure (RPP) interact in controlling renal haemodynamics in pentobarbitone-anaesthetized rabbits. 2. Renal blood flow (RBF) was reduced by electrical renal nerve stimulation (0.5-8 Hz), with RPP set using an extracorporeal circuit to 65, 100 and 135 mmHg. 3. Responses of RBF and cortical laser Doppler flux to renal nerve stimulation were blunted by increased RPP. For example, 4 Hz stimulation reduced RBF by 68 +/- 7% with baseline perfusion pressure approximately 65 mmHg, but only by 22 +/- 3% at approximately 135 mmHg. Medullary laser Doppler flux was less responsive than cortical laser Doppler flux to renal nerve stimulation and its response was not dependent on perfusion pressure. 4. When perfusion pressure was clamped at its baseline level during renal nerve stimulation, responses of RBF and cortical laser Doppler flux, but not medullary laser Doppler flux, were still blunted with increased baseline perfusion pressure. 5. A frequency rich stimulus was applied to assess the effects of perfusion pressure on dynamic neural control of RBF. Renal blood flow responded similarly at each level of perfusion pressure, as a low-pass filter with a pure time delay. 6. Our results suggest that, in the rabbit extracorporeal circuit model, increased RPP blunts the ability of steady state renal nerve stimulation to reduce cortical, but not medullary perfusion. However, in this model the level of RPP appears to have little impact on dynamic neural control of RBF.
引用
收藏
页码:35 / 45
页数:11
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