【摘要】 本实验观察了39只切断迷走神经的家兔在电刺激下丘脑背内侧核(DMH)对心外膜直流电图和跨膜电位的影响。结果发现:电刺激DMH 5分钟引起显著的TQ段和ST段偏移(P<0.05),静息膜电位变小(P<0.05),动作电位幅度减少(P<0.05),时程缩短(P<0.05)和Vmax减慢(P<0.05),心肌组织乳酸浓度增加(P<0.01)。α-受体阻滞剂酚妥拉明能阻断上述变化。表明:刺激DMH能引起心肌缺血和缺血性心电变化,其机理可能主要由心交感α-受体冠脉收缩作用所致。更多还原

【Abstract】 Effects of stimulating dorsomedial hypothalamic (DMH) nucleus on epicardial DC electrogram and myocardial transmembrane potentials were studied in 39 vagotomized rabbits. Five minutes of DMH stimulation induced shifts of TQ and ST segments(P<0.01), decreases of resting membrane potential(P<0.05) and action potential amplitude(P<0.05),shortening of APD80(P<0.05), reduction of Vmax(P<0.05)and increase of myocardial lactate concentration(P<0.01), α-Receptor blockade phentolamine could inhibit these changes induced by DMH stimulation. The results indicate that DMH stimulation can induce myocardial isehemia and ischemic electrocardiographic changes, the mechanism of which is probably due mainly to sympathetic α-receptor-mediated coronary vasoconstriction.更多还原