Morita H, Nishida Y, Hosomi H
Department of Physiology, Kagawa Medical School, Japan.
J Auton Nerv Syst. 1991 Jun 15;34(2-3):157-69. doi: 10.1016/0165-1838(91)90082-e.
We examined responses of renal nerve activity, urine flow, and urinary Na+ excretion to a hypertonic NaCl infusion in chronically instrumented conscious rabbits with unilateral renal denervation. The intravenous infusion of 20% NaCl, at 0.2 ml/min for 30 min, increased plasma osmolality by 27 +/- 5 mOsm/kg, and plasma Na+ by 16 +/- 3 mEq/l, and decreased hematocrit by 5 +/- 1%. These changes were accompanied by a marked decrease in renal nerve activity by 82 + 7%. Urine flow and urinary Na+ excretion increased gradually and peaked at the end of infusion. The innervated kidney excreted 23.3 +/- 3.3 ml urine and 5.5 +/- 0.7 mEq Na+ for the subsequent 60 min. However, the contralateral denervated kidney excreted only 9.5 +/- 2.0 ml urine and 2.2 +/- 0.6 mEq Na+; these values were significantly less than those of the innervated kidney. To examine the role of the sinoaortic and cardiopulmonary baroreceptors and the hepatic nerves in the response of renal nerve activity to the hypertonic NaCl infusion, renal nerve activity was examined in conscious rabbits with sinoaortic baroreceptor denervation (SAD) plus vagotomy and/or section of the anterior and posterior hepatic nerves (SAPH). In rabbits with SAD plus vagotomy or SAPH, the NaCl infusion also decreased renal nerve activity. After combining SAPH and SAD plus vagotomy, the decrease in renal nerve activity was completely blocked. These results indicate that hypertonic NaCl infusion elicits a marked decrease in renal nerve activity which is mediated predominantly by sinoaortic and cardiopulmonary baroreflexes and the hepatic nerves, and that the decrease in renal nerve activity plays an important role in the augmentation of renal function.
我们研究了在单侧肾去神经支配的慢性植入仪器的清醒兔中，肾神经活动、尿流率和尿钠排泄对高渗氯化钠输注的反应。以0.2 ml/min的速度静脉输注20%氯化钠30分钟，可使血浆渗透压升高27±5 mOsm/kg，血浆钠升高16±3 mEq/l，并使血细胞比容降低5±1%。这些变化伴随着肾神经活动显著降低82 + 7%。尿流率和尿钠排泄逐渐增加，并在输注结束时达到峰值。在随后的60分钟内，有神经支配的肾脏排泄23.3±3.3 ml尿液和5.5±0.7 mEq钠。然而，对侧去神经支配的肾脏仅排泄9.5±2.0 ml尿液和2.2±0.6 mEq钠；这些值明显低于有神经支配的肾脏。为了研究窦主动脉和心肺压力感受器以及肝神经在肾神经活动对高渗氯化钠输注反应中的作用，在窦主动脉压力感受器去神经支配（SAD）加迷走神经切断术和/或肝前、后神经切断术（SAPH）的清醒兔中检测肾神经活动。在SAD加迷走神经切断术或SAPH的兔中，氯化钠输注也降低了肾神经活动。在联合SAPH和SAD加迷走神经切断术后，肾神经活动的降低被完全阻断。这些结果表明，高渗氯化钠输注引起肾神经活动显著降低，这主要由窦主动脉和心肺压力反射以及肝神经介导，并且肾神经活动的降低在肾功能增强中起重要作用。
