CARDIOVASCULAR-RESPONSES TO BICUCULLINE IN THE PARAVENTRICULAR NUCLEUS OF THE RAT
CARDIOVASCULAR-RESPONSES TO BICUCULLINE IN THE PARAVENTRICULAR NUCLEUS OF THE RAT
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DOI：
10.1161/01.hyp.18.1.48
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发表时间：
1991-07-01
期刊：
影响因子：
8.3
通讯作者：
HAYWOOD, JR
中科院分区：
文献类型：
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作者：
MARTIN, DS;SEGURA, T;HAYWOOD, JR
本研究旨在探讨室旁核γ-氨基丁酸是否参与心血管功能的调节。 记录血压和心率，并在清醒的大鼠接受人工脑脊液或γ-氨基丁酸拮抗剂，bicuculline methiodide，双侧入室旁核微量输注血浆儿茶酚胺测定。 人工脑脊液对任何记录的变量都没有影响。 相比之下，将荷包牡丹碱注入室旁核区域可使血压（20 +/- 2 mm Hg）、心率（110 +/- 11次/min）以及去甲肾上腺素（640 +/- 107 pg/ml）和肾上腺素（1，266 +/- 267 pg/ml）的血浆浓度升高。 用神经节阻滞剂预处理可消除血压（-1 +/-2 mm Hg）和心率（5 +/-18次/min）效应。 双侧肾上腺髓质切除术显著降低了血浆去甲肾上腺素浓度的变化（81 +/- 14 pg/ml），并消除了血浆肾上腺素浓度的变化（5 +/- 4 pg/ml）。 相反，肾上腺髓质切除术仅轻微降低升压效应（18 +/- 2 mm Hg），而心率反应减弱（42 +/- 9次/min）约50%。 这些结果表明，内源性γ-氨基丁酸系统在下丘脑室旁核水平对交感神经系统产生紧张性抑制作用。
The present study was undertaken to determine whether gamma-aminobutyric acid in the paraventricular nucleus contributes to the regulation of cardiovascular function. Blood pressure and heart rate were recorded and plasma catecholamines were measured in conscious rats receiving microinfusions of either artificial cerebrospinal fluid or a gamma-aminobutyric acid antagonist, bicuculline methiodide, bilaterally into the paraventricular nucleus. Artificial cerebrospinal fluid had no effect on any of the recorded variables. In contrast, infusion of bicuculline into the region of the paraventricular nucleus produced increases in blood pressure (20 +/- 2 mm Hg), heart rate (110 +/- 11 beats/min), and plasma concentrations of norepinephrine (640 +/- 107 pg/ml) and epinephrine (1,266 +/- 267 pg/ml). Pretreatment with a ganglionic blocking agent abolished both the blood pressure (-1 +/- 2 mm Hg) and heart rate (5 +/- 18 beats/min) effects. Bilateral adrenal medullectomy reduced the changes in plasma norepinephrine concentrations (81 +/- 14 pg/ml) significantly and abolished the changes in plasma epinephrine concentrations (5 +/- 4 pg/ml). Conversely, adrenal medullectomy reduced the pressor effects (18 +/- 2 mm Hg) only slightly while the heart rate responses were attenuated (42 +/- 9 beats/min) by approximately 50%. These results suggest that an endogenous gamma-aminobutyric acid system exerts a tonic inhibitory effect on the sympathetic nervous system at the level of the paraventricular nucleus of the hypothalamus.