Robinette J B, Conger J D
Department of Medicine, University of Colorado Health Science Center, Denver.
J Clin Invest. 1990 Nov;86(5):1532-9. doi: 10.1172/JCI114872.
The roles of intrarenal angiotensin (A) and thromboxane (TX) in the vascular hypersensitivity to renal nerve stimulation (RNS) and paradoxical vasoconstriction to renal perfusion pressure (RPP) reduction in the autoregulatory range in 1 wk norepinephrine (NE)-induced acute renal failure (ARF) in rats were investigated. Renal blood flow (RBF) responses were determined before and during intrarenal infusion of an AII and TXA2 antagonist. Saralasin or SQ29548 alone partially corrected the slopes of RBF to RNS and RPP reduction in NE-ARF rats (P less than 0.02). Saralasin + SQ29548 normalized the RBF response to RNS. While combined saralasin + SQ29548 eliminated the vasoconstriction to RPP reduction, similar to the effect of renal denervation, appropriate vasodilatation was not restored. Renal vein norepinephrine efflux during RNS was disproportionately increased in NE-ARF (P less than 0.001) and was suppressed by saralasin + SQ29548 infusion (P less than 0.005). It is concluded that the enhanced sensitivity to RNS and paradoxical vasoconstriction to RPP reduction in 1 wk NE-ARF kidneys are the result of intrarenal TX and AII acceleration of neurotransmitter release to adrenergic nerve activity.
研究了肾内血管紧张素（A）和血栓素（TX）在大鼠1周去甲肾上腺素（NE）诱导的急性肾衰竭（ARF）中，对肾神经刺激（RNS）的血管超敏反应以及在自动调节范围内对肾灌注压（RPP）降低的反常血管收缩中的作用。在肾内输注血管紧张素II和血栓素A2拮抗剂之前和期间，测定肾血流量（RBF）反应。单独使用沙拉新或SQ29548可部分纠正NE-ARF大鼠中RBF对RNS和RPP降低的斜率（P<0.02）。沙拉新+SQ29548可使RBF对RNS的反应正常化。虽然沙拉新+SQ29548联合使用可消除对RPP降低的血管收缩，类似于肾去神经支配的效果，但未恢复适当的血管舒张。在RNS期间，NE-ARF大鼠肾静脉去甲肾上腺素流出量不成比例地增加（P<0.001），并被沙拉新+SQ29548输注所抑制（P<0.005）。结论是，1周NE-ARF肾脏对RNS的敏感性增强以及对RPP降低的反常血管收缩是肾内TX和AII加速神经递质释放至肾上腺素能神经活动的结果。
