Role of GABA within the nucleus tractus solitarii in the hypoxic ventilatory decline of awake rats
Role of GABA within the nucleus tractus solitarii in the hypoxic ventilatory decline of awake rats
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DOI：
10.1152/ajpregu.2001.281.5.r1411
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发表时间：
2001-11-01
影响因子：
2.8
通讯作者：
Shirato, K
中科院分区：
文献类型：
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作者：
Tabata, M;Kurosawa, H;Shirato, K
本研究的目的是检验我们的假设，即孤束核 (NTS) 中的 γ-氨基丁酸 (GABA) 可能与缺氧通气下降 (HVD) 有关，并且化学感受器刺激对于激活该机制至关重要。在这项研究中，我们使用了未麻醉、自由活动的老鼠。采用体内微透析技术测量细胞外GABA浓度([GABA](o))，采用体内微注射技术检测GABA激动剂和拮抗剂对缺氧时通气的影响。注射到 NTS 中的 GABA 激动剂会减弱缺氧期间的通气。通过缺氧暴露，[GABA](o) 在 HVD 期间增加。然而，通过颈动脉体去神经术（CBD），这种 GABA 的增加被消除了。尽管在 HVD 阶段将 GABA 拮抗剂微量注射到 NTS 中显着增加了通气抑制，但 CBD 消除了这种对通气的影响。这些结果表明 NTS 中的 GABA 在 HVD 中具有关键作用，并且如果没有化学感受器刺激，则该机制不会被激活。
The purpose of this study was to examine our hypothesis that gamma -aminobutyric acid (GABA) in the nucleus tractus solitarii (NTS) may be related to the hypoxic ventilatory decline (HVD) and that chemoreceptor stimulation was essential to activate this mechanism. We used unanesthetized, freely moving rats in this study. An in vivo microdialysis technique was used to measure the extracellular GABA concentration ([ GABA](o)), and an in vivo microinjection technique was used to examine the effects of the GABA agonists and antagonists on the ventilation during hypoxia. The GABA agonists injected into the NTS attenuated the ventilation during hypoxia. By hypoxic exposure, [GABA](o) was increased during the HVD. However, by carotid body denervation (CBD), this GABA increase was abolished. Although GABA antagonists microinjected into the NTS during the HVD phase significantly increased the depressed ventilation, this effect on the ventilation was abolished by CBD. These results suggest that the GABA in the NTS has a pivotal role in the HVD and that this mechanism is not activated without chemoreceptor stimulation.