Ishiki K, Morita H, Hosomi H
Department of Physiology, Kagawa Medical School, Japan.
J Auton Nerv Syst. 1991 Nov;36(2):139-48. doi: 10.1016/0165-1838(91)90110-o.
The reflex effects of hepatic osmoreceptors on the renal sympathetic nerve activity (RNA) were studied in 30 pentobarbital anesthetized, vagotomized and sino-aortic baroreceptor denervated (SAD + VD) rabbits. The changes in mean arterial pressure (MAP), heart rate (HR), and RNA were examined when 9% NaCl, 6.5% LiCl or 50% glucose solution was infused into the hepatic portal vein at a rate of 0.15 ml/kg/min for 10 min. Infusion of 9% NaCl solution into the hepatic portal vein increased the plasma osmolality by 10.8 +/- 1.0 mOsmol/kg from the control level in the blood of the hepatic portal vein and by 2.8 +/- 2.0 mOsmol/kg from the control level in the systemic blood. MAP was significantly elevated by 10.2 +/- 5.0 mmHg but HR did not change with hepatic portal infusion of 9% NaCl solution. Intraportal infusion of 9% NaCl solution significantly decreased the RNA by 28.6-34.2% from the control level, 6.5% LiCl solution by 28.6 +/- 4.7%, and 50% glucose solution by 26.2 +/- 3.0%. Femoral arterial infusion of hypertonic NaCl solution, however, did not evoke any significant change in RNA in SAD + VD rabbits. These findings suggest that increases in osmolality and NaCl concentration in the systemic circulation do not result in a decrease of RNA. Furthermore, after section of the anterior and posterior plexus of the hepatic nerve, hepatic portal infusion of hypertonic NaCl solution elicited no change in RNA. The present data indicate that an increase in osmolality in the hepatic portal venous blood results in a reflex decrease of RNA. This reflex may be important for restoration of a postprandial increase in osmolality.
在30只戊巴比妥麻醉、迷走神经切断且去窦主动脉压力感受器（SAD + VD）的家兔中，研究了肝脏渗透压感受器对肾交感神经活动（RNA）的反射作用。以0.15 ml/kg/min的速率向肝门静脉输注9% NaCl、6.5% LiCl或50%葡萄糖溶液10分钟，检测平均动脉压（MAP）、心率（HR）和RNA的变化。向肝门静脉输注9% NaCl溶液，使肝门静脉血中血浆渗透压较对照水平升高10.8±1.0 mOsmol/kg，全身血中较对照水平升高2.8±2.0 mOsmol/kg。肝门静脉输注9% NaCl溶液使MAP显著升高10.2±5.0 mmHg，但HR未改变。肝门静脉输注9% NaCl溶液使RNA较对照水平显著降低28.6 - 34.2%，6.5% LiCl溶液使其降低28.6±4.7%，50%葡萄糖溶液使其降低26.2±3.0%。然而，在SAD + VD家兔中，股动脉输注高渗NaCl溶液并未引起RNA的任何显著变化。这些发现表明，全身循环中渗透压和NaCl浓度的升高不会导致RNA降低。此外，切断肝神经前后丛后，肝门静脉输注高渗NaCl溶液未引起RNA变化。目前的数据表明，肝门静脉血中渗透压升高导致RNA反射性降低。这种反射对于恢复餐后渗透压升高可能很重要。
