Acute inhibition of the hypothalamic paraventricular nucleus decreases renal sympathetic nerve activity and arterial blood pressure in water-deprived rats.
Acute inhibition of the hypothalamic paraventricular nucleus decreases renal sympathetic nerve activity and arterial blood pressure in water-deprived rats.
复制标题
急性抑制下丘脑室旁核会降低缺水大鼠的肾交感神经活动和动脉血压。
DOI：
10.1152/ajpregu.00494.2003
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Toney,GlennM
中科院分区：
文献类型：
--
作者：
Stocker,SeanD;Keith,KimberlyJ;Toney,GlennM
The present study was performed to determine whether sympathetic outflow and arterial blood pressure in water-deprived rats are dependent on the ongoing neuronal activity of the hypothalamic paraventricular nucleus (PVN). Renal sympathetic nerve activity (RSNA), mean arterial blood pressure (MAP), and heart rate were recorded in urethane-α-chloralose-anesthetized rats that were deprived of water but not food for 48 h before experiments. Acute inhibition of the PVN by bilateral microinjection of the GABAAagonist muscimol (100 pmol/side) significantly decreased RSNA in water-deprived rats (-26.7 ± 4.7%,n= 7) but was without effect in control rats (1.3 ± 6.3%,n= 7). Similarly, injection of muscimol produced a greater decrease in MAP in water-deprived rats than in control rats (-46 ± 3 vs. -16 ± 3 mmHg, respectively), although baseline MAP was not different between groups (105 ± 4 vs. 107 ± 4 mmHg, respectively). Neither bilateral microinjection of isotonic saline vehicle (100 nl/side) into the PVN nor muscimol (100 pmol/side) outside the PVN altered RSNA or MAP in either group. In addition, ganglionic blockade with hexamethonium (30 mg/kg iv) significantly decreased MAP in both groups; however, the decrease in MAP was significantly greater in water-deprived rats than in control rats (62 ± 2 vs. 48 ± 2 mmHg, respectively). Collectively, these findings suggest that sympathetic outflow contributes more to the maintenance of blood pressure in the water-deprived rat, and this depends, at least partly, on the ongoing activity of PVN neurons.
