An analysis of the mechanism by which gamma-aminobutyric acid depresses ventilation in the rat.
An analysis of the mechanism by which gamma-aminobutyric acid depresses ventilation in the rat.
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γ-氨基丁酸抑制大鼠通气的机制分析。
DOI：
10.1152/jappl.1984.56.4.849
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
J. Jonason
中科院分区：
文献类型：
--
作者：
J. Hedner;T. Hedner;P. Wessberg;J. Jonason
在氟烷麻醉的大鼠中，侧脑室注射γ-氨基丁酸（GABA）或腹腔注射GABA转氨酶A抑制剂氨氧乙酸（AOAA）可抑制通气。GABA引起的呼吸频率（f）和潮气量（VT）的变化导致了AOAA的降低，而AOAA仅引起f的降低。脑室内GABA降低吸气驱动（VT/TI; 100 ms时的肺内压），但不改变球脑桥设置的吸气持续时间（TI）。此外，呼吸占空比（TI/TT）降低，对CO2暴露的呼吸反应减弱。GABA拮抗剂荷包牡丹碱可逆转GABA引起的兴奋性抑制。在AOAA给药后45分钟测量的GABA含量在全脑、半球、纹状体和脊髓下部区域中显著增加。全脑GABA含量与f、分钟通气量、TI、呼气时程（TE）和总周期时程的变化显著相关。脑干GABA含量与TI/TT呈显著负相关，与VT/TI无显著相关性。总之，GABA似乎与大脑中不同水平的呼吸中枢调节相互作用。然而，内源性GABA浓度增加的主要影响是由于TE延长而导致呼吸频率降低。
Intracerebroventricular administration of gamma-aminobutyric acid (GABA) or intraperitoneal injection of the GABA transaminase A inhibitor aminooxyacetic acid (AOAA) depressed ventilation in halothane-anesthetized rats. The depression was due to changes in both respiratory frequency (f) and tidal volume (VT) after GABA, whereas AOAA decreased only f. Intracerebroventricular GABA decreased inspiratory drive (VT/TI; intrapulmonary pressure at 100 ms) but did not change the bulbopontine setting of inspiratory duration (TI). Moreover, respiratory duty cycle (TI/TT) was decreased, and the ventilatory response to CO2 exposure was blunted. The ventilatory depression induced by GABA was reversed by the GABA antagonist bicuculline. The GABA content measured 45 min after AOAA administration was significantly increased in the whole brain, the hemispheres, striatum, and lower spinal cord regions. Whole-brain GABA content was significantly correlated to the changes in f, minute ventilation, TI, expiratory duration (TE), and total cycle duration. Furthermore, there was a significant negative correlation between brain stem GABA content and TI/TT but not VT/TI. In summary, GABA seems to interact with the central regulation of respiration at different levels in the brain. The main effect of increased endogenous concentrations of GABA is, however, a decrease in respiratory frequency due to a prolongation in TE.