Hypothalamic paraventricular nucleus differentially supports lumbar and renal sympathetic outflow in water-deprived rats.
Hypothalamic paraventricular nucleus differentially supports lumbar and renal sympathetic outflow in water-deprived rats.
复制标题
下丘脑室旁核对缺水大鼠的腰交感神经和肾交感神经流出有不同的支持。
DOI：
10.1113/jphysiol.2004.076661
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发表时间：
2005
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;Hunwick,KimberlyJ;Toney,GlennM
The present study sought to determine whether the hypothalamic paraventricular nucleus (PVN) contributes in a time‐dependent manner to the differential patterning of lumbar and renal sympathetic nerve activity (SNA) in water‐deprived rats. Mean arterial blood pressure (MAP) and both lumbar SNA (LSNA) and renal SNA (RSNA) were recorded simultaneously in control, 24 and 48 h water‐deprived rats, and the PVN was inhibited bilaterally with microinjection of the GABAAagonist muscimol (100 pmol in 100 nl per side). Inhibition of the PVN significantly decreased RSNA in 48 h water‐deprived rats but not in 24 h water‐deprived or control rats (48 h, −17 ± 4%; 24 h, −2 ± 5%; control, 4 ± 6%;P< 0.05). In addition, injection of muscimol significantly decreased LSNA in 48 and 24 h water‐deprived rats but not in control rats (48 h, −41 ± 4%; 24 h, −14 ± 6%; control, −3 ± 2%;P< 0.05). Interestingly, the decrease in LSNA was significantly greater than the decrease in RSNA of 24 and 48 h water‐deprived rats (P< 0.05). Inhibition of the PVN also significantly decreased MAP to a greater extent in 48 and 24 h water‐deprived rats compared to control rats (48 h, −34 ± 5 mmHg; 24 h, −26 ± 4 mmHg; control, −15 ± 3 mmHg;P< 0.05). When 48 h water‐deprived rats were acutely rehydrated by giving access to tap water 2 h before experiments, inhibition of the PVN with muscimol did not alter LSNA (−12 ± 8%) or RSNA (7 ± 4%) but did produce a small decrease in MAP (−15 ± 4 mmHg) that was not different from control rats. In a parallel set of experiments, acute rehydration of 48 h water‐deprived rats significantly attenuated the increased Fos immunoreactivity in PVN neurones that project to the spinal cord or rostral ventrolateral medulla. Collectively, the present findings suggest that PVN autonomic neurones are synaptically influenced during water deprivation, and that these neurones differentially contribute to LSNA and RSNA in water‐deprived rats.
