Asayama J, Yamahara Y, Tatsumi T, Matsumoto T, Miyazaki H, Sakai R, Inoue M, Omori I, Inoue D, Nakagawa M
Second Department of Medicine, Kyoto Prefectural University of Medicine, Japan.
Jpn Circ J. 1992 Mar;56(3):292-300. doi: 10.1253/jcj.56.292.
This study was designed to investigate effects of quiescence by cessation of electrical stimulation during the first stage of reoxygenation on recovery of mechanical function from hypoxia-induced contractile dysfunction in papillary muscles and effects of the absence of cardiac output on myocardial energetic metabolism of post-ischemic hearts. (1) Regular contractions and postextrasystolic contraction were evoked. After 120 min hypoxia, muscles were reoxygenated. In muscles of quiescence during the first 30 min reoxygenation, the recovery of regular contractions was better than that in muscles in which programmed stimulation was continued. However, the quiescence had no effect on the recovery of post-extrasystolic contractions from hypoxia-induced contractile dysfunction. (2) Isolated hearts were perfused either according to Langendorff technique or as working heart preparations. After 40 min ischemia, hearts were reperfused for 25 min. Although there was no difference in energy charge of myocardium between 2 modes of reperfusion, % incidence of sustained ventricular fibrillation in muscles in which non-working mode was maintained for the first step of reperfusion was lower than that in which working mode was continued. We presume that the reduction of contractile work during the initial step of reperfusion is of value for cardio-protection.
本研究旨在探讨复氧第一阶段通过停止电刺激实现的静息状态对乳头肌缺氧诱导的收缩功能障碍后机械功能恢复的影响，以及心输出量缺失对缺血后心脏心肌能量代谢的影响。（1）诱发规律性收缩和期外收缩后，进行120分钟缺氧处理，随后对肌肉进行复氧。在复氧的前30分钟处于静息状态的肌肉中，规律性收缩的恢复情况优于继续进行程控刺激的肌肉。然而，静息状态对缺氧诱导的收缩功能障碍后期外收缩的恢复没有影响。（2）采用Langendorff技术或作为工作心脏标本对离体心脏进行灌注。缺血40分钟后，心脏再灌注25分钟。尽管两种再灌注模式下心肌的能荷没有差异，但在再灌注第一步维持非工作模式的肌肉中，持续性室颤的发生率低于继续维持工作模式的肌肉。我们推测，再灌注初始阶段收缩功的降低对心脏保护具有重要意义。
