应激所致大鼠心室电稳定性的改变

Stress-induced Changes of Ventricular Electric Stability of Rats

本文研究了制动应激不同时程对大鼠心室电稳定性(VES)的影响.制动2小时,心率明显增快,脑室注射乌头碱(Aco,7.5μg.kg^(-1))出现室速(VT)潜伏期明显缩短,心肌组织cAMP含量升高,提示心脏交感神经兴,VES下降.而制动8小时,上述指标均呈反相变化,提示心脏交感神经抑制,VES升高.因此,持续制动应激,大鼠VES表现为先下降后上升.其机制可能与交感神经活性有关.

Changes of ventricular electric stability (VES) in rats caused by immobi-lized stress for different length of time were studied. After 2 hours' immobilized stress,there was an obvious increase in heart rate,shortened latent period of ventricular techycardia after icv aconitine (Aco,7.5μg·kg-1),an increase in myocardial cAMP concentration suggesting cardiac sympathetic stimulation with decreased VES. Whereas after 8 hours' immobilized stress,On the contrary,the reversal of all the aforementioned features occurred implying a decreased sympathetic activity with increased VES. Thus, persistent immobilized stress caused an initial decreased VES which was followed by subsequent increase in VES. The mechanism of this chang may be attributed to the activities of sympathetic nervous system.