Central mechanism of domato-parasympathetic reflex vasodilatation

我们测量了舌神经（LN）或三叉神经脊髓核（Vsp）刺激引起的下唇血流和全身动脉血压（SABP）的变化，以深入了解脑干对伤害性刺激的交感和副交感反应的整合。我们使用人工通风，颈部迷走神经交感切除猫与a-氯氯蔗糖和氨基甲酸乙酯深度麻醉。在电刺激Vsp或LN后，无论SABP是增加还是减少，唇血流量（LBF）都以强度和频率依赖的方式增加。相比之下，电刺激Vsp或LN引起的SABP变化没有明显的最佳频率。LBF的增加幅度与SABP的变化幅度没有关系。微注射利多卡因或kainic酸分别对LN刺激引起的LBF增加和SABP变化有可逆和不可逆的抑制作用。当单侧直接微注射到同侧Vsp时，GABA激动剂muscimol消除了lnn引起的唇血流量增加和SABP变化，而不改变基底SABP，这表明在Vsp中存在GABA能系统调节副交感神经介导的LBF增加和交感神经介导的SABP变化。利多卡因微注射到唾液核中，可明显减弱ln诱导的血流量增加，但对ln诱导的SABP变化无影响。因此，介导ln诱导的LBF增加的神经通路似乎很简单，至少需要四个神经元：三叉神经传入- Vsp副交感神经节前神经元，细胞体位于下流涎核-神经节后神经元。另一方面，诱发SABP变化的途径似乎更复杂，可能受到更多因素的影响，这可能是通过改变交感神经活动介导的。少

We measured the changes in lower lip blood flow and systemic arterial blood pressure (SABP) evoked by lingual nerve (LN) or trigeminal spinal nucleus (Vsp) stimulation to gain an insight into the brainstem integration of sympathetic and parasympathetic responses to nociceptive stimulation. We used artificially ventilated, cervically vago-sympathectomized cats deeply anesthetized with a-chloralose and urethane. A lip blood flow (LBF) increase occurred in an intensity- and frequency-dependent manner following electrical stimulation of Vsp or LN regardless of whether SABP increased or decreased. In contrast, there was no apparent optimal frequency for the changes in SABP elicited by electrical stimulation of Vsp or LN. No relationship was found between the amplitude of the LBF increase and that of the SABP change. Microinjection of lidocaine or kainic acid into the Vsp evoked, respectively, reversible and irreversible inhibition of the LBF increase and SABP change evoked by LN stimulation … More . When microinjected unilaterally directly into the ipsilateral Vsp, the GABA agonist muscimol abolished the LN-evoked increase in lip blood flow and changes in SABP without changing basal SABP, suggesting the presence in the Vsp of a GABAergic system modulating both the parasympathetically mediated LBF increase and the sympathetically mediated SABP change. Lidocaine microinjection into the salivatory nucleus caused a significant attenuation of the LN-induced blood flow increase, but had no effect on the LN-induced SABP change. Thus, the neural pathway mediating the LN-induced LBF increase seems to be simple, requiring a minimum of four neurons : trigeminal afferent - Vsp parasympathetic pre-ganglionic neurons with cell body located in the inferior salivatory nucleus - otic postganglionic neuron. On the other hand, the pathway underlying the evoked SABP changes, presumably mediated via altered sympathetic activity, seems to be more complicated and could be affected by more numerous factors. Less