Parasympathetic reflex vasodilation in the cerebral hemodynamics of rats
Parasympathetic reflex vasodilation in the cerebral hemodynamics of rats
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DOI：
10.1007/s00360-014-0807-2
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发表时间：
2014-04-01
影响因子：
2
通讯作者：
Izumi, Hiroshi
中科院分区：
文献类型：
--
作者：
Ishii, Hisayoshi;Sato, Toshiya;Izumi, Hiroshi
我们研究了副交感神经反射血管舒张在脑血流动力学调节中的作用，以及GABA（A）受体是否调节这种反应。本文观察了三叉神经传入对麻醉大鼠颈内动脉血流和顶叶皮层脑血管的影响。电刺激舌神经（LN）的中央切断端引起ICABF的强度和频率依赖性增加，独立于颈外动脉血流的变化。增加ICABF引起的LN刺激，无论是否存在交感神经支配。LN刺激引起的ICABF增加几乎被静脉注射六甲双铵（10 mg kg（-1））消除，并被阿托品（0.1 mg kg（-1））显著降低。虽然单独的LN刺激对rCBF没有显著影响，但LN刺激与GABA（A）受体阻断剂戊四唑联合使用可显著增加rCBF。这种rCBF的增加被六甲双铵和阿托品的给药显著降低。这些观察结果表明，ICABF和rCBF的增加是通过三叉神经介导的反射由副交感神经激活引起的。由LN刺激引起的rCBF增加被认为受到中枢神经系统中GABA（A）受体的限制。这些结果表明，副交感神经反射血管扩张和GABA受体介导的调制在脑干突触传递参与三叉神经传入输入的脑血流动力学的调节。
We investigated the role of parasympathetic reflex vasodilation in the regulation of the cerebral hemodynamics, and whether GABA(A) receptors modulate the response. We examined the effects of activation of the parasympathetic fibers through trigeminal afferent inputs on blood flow in the internal carotid artery (ICABF) and the cerebral blood vessels (rCBF) in parietal cortex in urethane-anesthetized rats. Electrical stimulation of the central cut end of the lingual nerve (LN) elicited intensity- and frequency-dependent increases in ICABF that were independent of changes in external carotid artery blood flow. Increases in ICABF were elicited by LN stimulation regardless of the presence or absence of sympathetic innervation. The ICABF increases evoked by LN stimulation were almost abolished by the intravenous administration of hexamethonium (10 mg kg(-1)) and were reduced significantly by atropine administration (0.1 mg kg(-1)). Although the LN stimulation alone had no significant effect on rCBF, LN stimulation in combination with a blocker of the GABA(A) receptor pentylenetetrazole increased the rCBF markedly. This increase in rCBF was reduced significantly by the administration of hexamethonium and atropine. These observations indicate that the increases in both ICABF and rCBF are evoked by parasympathetic activation via the trigeminal-mediated reflex. The rCBF increase evoked by LN stimulation is thought to be limited by the GABA(A) receptors in the central nervous system. These results suggest that the parasympathetic reflex vasodilation and its modulation mediated by GABA receptors within synaptic transmission in the brainstem are involved in the regulation of the cerebral hemodynamics during trigeminal afferent inputs.