Suppression and augmentation of trigeminal depressor response

抑制和增强三叉神经降压反应

• 批准号: 14370652
• 负责人: KAMEKURA Nobuhito
• 金额: $ 8.83万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14370652/
• 关键词: autonomic nerve; trigeminal nerve; hemodynamics; tirgeminla depressor response; aortic depressor nerve; arterial baroreflex

Decrease in cerebral blood flow is one of the most common complications in dental practice. Trigeminal stimulation plays an important role and baroreflex seems to participate in this complication. Therefore we examined hemodynamic responses and autonomic nerve activities (renal sympathetic nerve activity : RSNA, vagal nerve activity : VNA) when we stimulated trigeminal nerve and evoked arterial baroreflex. In addition, we examined effects of some agents (propofol, fentanyl, isoflurane and phentolamine) on hemodynamic response and autonomic nerve activity during stimuli of trigeminal nerve.This study was performed on rabbits. Arterial baroreflex was evoked with stimuli of aortic depressor nerve (ADN). Low frequency stimulation (5 Hz) of infraorbital nerve (ION) reduced mean arterial blood pressure (MAP), heart rate (HR) and RSNA significantly. High frequency stimulation (25 Hz) of ION caused a biphasic change, an early fall of MAP and a subsequent rise of MAP. Change of RSNA was also biphasic.To examine the effect of arterial baroreflex, simultaneous stimuli of ION (5 Hz) and ADN were performed. Depressor response evoked with simultaneous stimuli was greater than that evoked with ION alone. On the other hand, during stimuli of ION (25 Hz) and ADN, presser response which was observed during stimulation of ION alone was suppressed significantly. Change of RSNA was similar to the change of MAP.Propofol suppressed presser response during stimuli of ION and fentanyl suppressed depressor response in dosage dependence. Combination of propofol and fentanyl suppressed depressor and presser responses but arterial baroreflex still remained. Isoflurane suppressed changes of MAP and RSNA during stimuli of ION, but decrease in MAP before stimuli of ION was remarkable and arterial baroreflex was suppressed. Phentolamine suppressed presser and depressor response, but the change of RSNA was observed similarly before administration.

脑血流量减少是牙科实践中最常见的并发症之一。三叉神经刺激起着重要作用，压力感受性反射似乎参与了这一并发症。因此，我们检查了血流动力学反应和自主神经活动（肾交感神经活动：RSNA，迷走神经活动：VNA），当我们刺激三叉神经和诱发动脉压力反射。此外，我们还观察了异丙酚、芬太尼、异氟醚和酚妥拉明等麻醉剂对刺激家兔三叉神经时血流动力学和自主神经活动的影响。刺激主动脉减压神经（ADN）诱发动脉压力感受性反射。低频（5Hz）刺激眶下神经（ION）可显著降低平均动脉压（MAP）、心率（HR）和RSNA。高频（25Hz）刺激ION引起MAP先下降后上升的双相变化。同时刺激ION（5Hz）和ADN，观察其对动脉压力感受性反射的影响。同时刺激诱发的降压反应大于单独ION诱发的降压反应。另一方面，在刺激ION（25 Hz）和ADN时，在单独刺激ION时观察到的按压反应被显著抑制。RSNA的变化与MAP的变化相似，异丙酚抑制ION刺激时的加压反应，芬太尼抑制降压反应，呈剂量依赖性。异丙酚和芬太尼联合应用抑制降压和加压反应，但动脉压力反射仍存在。异氟醚抑制ION刺激时MAP和RSNA的变化，但ION刺激前MAP下降明显，动脉压力感受性反射受到抑制。酚妥拉明抑制升压和降压反应，但RSNA的变化与给药前相似。