Cardiovascular responses evoked by activation or blockade of GABAA receptors in the hypothalamic PVN are attenuated in transgenic rats with low brain angiotensinogen
Cardiovascular responses evoked by activation or blockade of GABAA receptors in the hypothalamic PVN are attenuated in transgenic rats with low brain angiotensinogen
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DOI：
10.1016/j.brainres.2012.02.021
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发表时间：
2012-04-11
期刊：
影响因子：
2.9
通讯作者：
Fontes, Marco Antonio P.
中科院分区：
文献类型：
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作者：
Gomes da Silva, Ana Quenia;Xavier, Carlos Henrique;Fontes, Marco Antonio P.
先前的证据表明，PVN中抑制性GABA能和兴奋性血管紧张素能因子之间的平衡对心血管控制很重要。在低脑血管紧张素原转基因大鼠中，研究了激活或阻断室旁核(PVN)中GABA(A)受体引起的心血管反应。同时测定脑血管紧张素Ⅱ和血管紧张素-(1-7)水平。在功能实验中，用乌拉坦麻醉TGR(ASrAOGEN)大鼠和SD大鼠(SD，对照组)，记录血压(BP)、心率(HR)和肾交感神经活动(RSNA)。与SD大鼠相比，TGR(ASrAOGEN)大鼠脑内Ang II和Ang-(1-7)水平显著降低。用GABAA激动剂Muscimol(1nmol/100nL)抑制PVN神经元后，与SD大鼠相比，TGR(ASrAOGEN)大鼠的所有心血管变量的下降都有所减弱。这一差异在HR中尤为明显(TGR Mus-23+/-6 bpm vs-77+/-9 bpm SD Mus；P
Previous evidence indicates that a balance between inhibitory gabaergic and excitatory angiotensinergic factors in the PVN is important for cardiovascular control. We investigated the cardiovascular response evoked from activation or blockade of GABA(A) receptors in the paraventricular nucleus (PVN), in transgenic rats with low brain angiotensinogen [TGR(ASrAOGEN)]. Brain Ang II and Ang-(1-7) levels were also determined. In functional experiments, TGR(ASrAOGEN) and Sprague Dawley rats (SD, control) were anesthetized with urethane and blood pressure (BP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were recorded. Brain Ang II and Ang-(1-7) levels were largely reduced in TGR(ASrAOGEN) compared with SD rats. Inhibition of PVN neurons with the GABAA agonist, muscimol (1 nmol/100 nL), resulted in an attenuated fall in all cardiovascular variables in TGR(ASrAOGEN) compared with SD rats. This difference was particularly pronounced in HR (TGR Mus -23 +/- 6 bpm vs. -77 +/- 9 bpm SD Mus; P