GABAB receptors in the NTS mediate the inhibitory effect of trigeminal nociceptive inputs on parasympathetic reflex vasodilation in the rat masseter muscle
GABAB receptors in the NTS mediate the inhibitory effect of trigeminal nociceptive inputs on parasympathetic reflex vasodilation in the rat masseter muscle
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DOI：
10.1152/ajpregu.00569.2011
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发表时间：
2012-03-01
影响因子：
2.8
通讯作者：
Izumi, Hiroshi
中科院分区：
文献类型：
--
作者：
Ishii, Hisayoshi;Izumi, Hiroshi
石井H，泉H.孤束核内的GABA（B）受体介导三叉神经伤害性传入对大鼠咬肌副交感反射血管舒张的抑制作用。Am J Physiol Regul Integr Comp Physiol 302：R776-R784，2012年。首次发表于2012年1月4日; doi：10.1152/ajpregu.00569.2011。本研究的目的是检查是否三叉神经伤害性输入参与的调制副交感神经反射血管舒张的颌肌。本研究通过观察辣椒素对口面区的伤害性刺激，以及孤束核（NTS）内微量注射GABA（A）和GABA（B）受体激动剂或拮抗剂对麻醉大鼠咬肌血流动力学的影响来完成。电刺激双侧交感神经切除动物的颈迷走神经（cVN）中央切断端可增加咬肌（MBF）的血流量。在cVN刺激引起的MBF的增加显着减少后，辣椒素注射到舌前的分布的舌神经或下唇，但不是当注射到皮肤的足背。辣椒素注射液对刺激cVN引起的MBF增加的抑制作用，在NTS内微量注射GABA（B）受体激动剂巴氯芬后，无明显改变。孤束核内微量注射GABA（B）受体拮抗剂CGP-35348可明显减弱辣椒素对刺激cVN引起的MBF增加的抑制作用，而微量注射GABA（A）受体拮抗剂荷包牡丹碱则无此作用。我们的研究结果表明，三叉神经伤害性输入抑制迷走-副交感神经反射的咬肌血管扩张，并建议GABA（B），而不是GABA（A）受体的激活下观察到的抑制NTS。
Ishii H, Izumi H. GABA(B) receptors in the NTS mediate the inhibitory effect of trigeminal nociceptive inputs on parasympathetic reflex vasodilation in the rat masseter muscle. Am J Physiol Regul Integr Comp Physiol 302: R776-R784, 2012. First published January 4, 2012; doi:10.1152/ajpregu.00569.2011.-The present study was designed to examine whether trigeminal nociceptive inputs are involved in the modulation of parasympathetic reflex vasodilation in the jaw muscles. This was accomplished by investigating the effects of noxious stimulation to the orofacial area with capsaicin, and by microinjecting GABA(A) and GABA(B) receptor agonists or antagonists into the nucleus of the solitary tract (NTS), on masseter hemodynamics in urethane-anesthetized rats. Electrical stimulation of the central cut end of the cervical vagus nerve (cVN) in sympathectomized animals bilaterally increased blood flow in the masseter muscle (MBF). Increases in MBF evoked by cVN stimulation were markedly reduced following injection of capsaicin into the anterior tongue in the distribution of the lingual nerve or lower lip, but not when injected into the skin of the dorsum of the foot. Intravenous administration of either phentolamine or propranolol had no effect on the inhibitory effects of capsaicin injection on the increases of MBF evoked by cVN stimulation, which were largely abolished by microinjecting the GABA(B) receptor agonist baclofen into the NTS. Microinjection of the GABA(B) receptor antagonist CGP-35348 into the NTS markedly attenuated the capsaicin-induced inhibition of MBF increase evoked by cVN stimulation, while microinjection of the GABA(A) receptor antagonist bicuculline did not. Our results indicate that trigeminal nociceptive inputs inhibit vagal-parasympathetic reflex vasodilation in the masseter muscle and suggest that the activation of GABA(B) rather than GABA(A) receptors underlies the observed inhibition in the NTS.