刺激犬体表感受器对心脏表面神经元和心脏功能的影响

为了给“抑制死”提供实验根据和理论依据,模拟“抑制死”的体表刺激,用3.0kg触压麻醉开胸犬的心前区、剑突下,同步记录大右心房神经节丛神经元内单位放电的频数及心脏变时。变力性反应。静脉给入普来洛尔（1mg／kg）或阿托品（1mg／kg）及心脏急性会神经支配后,重复上述刺激。结果显示：触压犬心前区可直接引起心脏表面神经节丛内的副交感神经元兴奋,窦房结自律性降低,引起负性频率作用;在此基础上刺激兴奋心脏表面交感神经元可诱发室性心律失常。提示刺激心前区、剑突下引起的“抑制死”,不仅与迷走神经对心脏的抑制有关,可能还与交感神经元对心室的兴奋有关。

Bradycardia and ventricular arrhythmia induced by pressing at the precordial and the hypoxiphoid region activating the canine intrinsic cardiac neurons

For the purpose of studying the mechanism of "cardio-inhibitory death", the canine intrinsic cardiac neuronal spontaneous activity and inotropic and chronotropic responses were recorded following pressing at the precordial and the hypoxiphoid region of the anesthetized chest-open d0gs with 3kg weight. To stimulate the canine repeatedly after intravenous administration of the propranol (1mg' kg-1 , iv. ) or atropine (1mg'·kg-1, iv. )and following acute decentralization. Pressing at the precordial region could stimulate the parasympathetic ganglion, and then induced bradycardia and stimulate the sympathetic neurons induced the ventrlcular arrhythmia. This experiment suggested that the "cardial inhibitory death" can be induced by stimulating the precordial and hypoxiphoid region was not only due to the parasympathetic inhibiting effect on the heart, but also might be due to the exciting effect on the ventricular exerted by the sympathetic neuron.