Hayashi T, Shibamoto T, Yamaguchi Y, Wang H G, Tanaka S
Department of Physiology, Division 2, Shinshu University School of Medicine, Asahi, Matsumoto, Nagano, Japan.
Can J Physiol Pharmacol. 1995 Oct;73(10):1495-501. doi: 10.1139/y95-207.
Hypotension occurring during hemodialysis is often accompanied by paradoxical bradycardia. However, the mechanism is poorly understood. This study was designed to determine the role of the sympathetic nervous system in hemodialysis-induced hypotension and bradycardia. We measured efferent sympathetic nerve activities to the heart (CNA), kidney (RNA), liver (HNA), spleen (SpNA), and adrenal gland (AdNA), along with heart rate (HR), blood pressure (BP), central venous pressure (CVP), and left atrial pressure (LAP) during hemofiltration performed at a rate of 0.3 mL .center dot Kg(-1) center dot min(-1) for 30 min in anesthetized dogs. The response to hemorrhage was also studied at the same bleeding speed. Hemorrhage caused a decrease in BP (-18 +/- 1 mmHg; 1 mmHg = 133.3 Pa) with reflex increases in HR (7 +/- 2 beats/min) and sympathetic nerve activities. In contrast, hemofiltration caused a decrease in CNA (85 +/- 18%), HNA (86 +/- 11%), and SpNA (88 +/- 11%) with greater decreases in BP (-43 +/- 10 mmHg) and HR (-27 +/- 14 beats/min) than hemorrhage. During hemofiltration, the decreases in BP, HR, CNA, HNA, and SpNA were attenuated after vagotomy. Hematocrit increased by 6.5% at 30 min after hemofiltration, whereas it decreased by 4.3% after hemorrhage. These results suggest that hemofiltration suppresses the sympathetic nervous system, resulting in decreases in HR and BP. Furthermore, this sympathetic suppression during hemofiltration is mediated by vagal afferents.
血液透析期间发生的低血压常伴有反常性心动过缓。然而，其机制尚不清楚。本研究旨在确定交感神经系统在血液透析诱导的低血压和心动过缓中的作用。我们在麻醉犬身上以0.3 mL·kg⁻¹·min⁻¹的速率进行30分钟血液滤过期间，测量了心脏（CNA）、肾脏（RNA）、肝脏（HNA）、脾脏（SpNA）和肾上腺（AdNA）的传出交感神经活动，以及心率（HR）、血压（BP）、中心静脉压（CVP）和左心房压（LAP）。还以相同的出血速度研究了对出血的反应。出血导致血压下降（-18±1 mmHg；1 mmHg = 133.3 Pa），心率（7±2次/分钟）和交感神经活动反射性增加。相比之下，血液滤过导致CNA（85±18%）、HNA（86±11%）和SpNA（88±11%）下降，血压（-43±10 mmHg）和心率（-27±14次/分钟）的下降幅度大于出血。在血液滤过期间，迷走神经切断术后血压、心率、CNA、HNA和SpNA的下降减弱。血液滤过30分钟后血细胞比容增加6.5%，而出血后血细胞比容下降4.3%。这些结果表明，血液滤过抑制交感神经系统，导致心率和血压下降。此外，血液滤过期间的这种交感抑制是由迷走神经传入介导的。
