Iliodromitis E K, Papadopoulos C, Paraskevaidis I A, Kyriakides Z S, Flessa C, Kremastinos D T
Onassis Cardiac Surgery Center, 2nd Department of Cardiology, Athens, Greece.
Cardiovasc Drugs Ther. 1996 Jul;10(3):341-6. doi: 10.1007/BF02627958.
The aim of this study was to evaluate the way in which short-term protection declines and is eventually lost in preconditioning and to determine the efficacy of a second preconditioning at various reperfusion intervals. Male rabbits were divided into six groups. Forty-five minutes (sustained) ischemia followed by 120 minutes reperfusion was applied 60, 65, 70, 75, and 80 minutes after a 5 minute preconditioning (groups A, B, C, D, and E) and in a control group (F) after no preconditioning. The infarct to risk ratio (I/R) was 38.3 +/- 3.5% in group A, 46.0 +/- 7.8% in B, 61.6 +/- 9.7% in C, 68.1 +/- 4.2% in D, 64.5 +/- 7.8% in E, and 61.0 +/- 7.7% in F. Group A had a smaller I/R compared with groups C, D, E, and F (p < 0.05). In another series, groups G, H, and I were exposed to two 5-minute preconditioning stimuli, separated, respectively, by 45, 60, and 75 minutes of reperfusion; 10 minutes after the last preconditioning, the animals were exposed to 45-minutes ischemia and 120 minutes reperfusion. Groups A and D (with the smaller and higher I/R ratio) were also incorporated into this protocol in order to compare the effect of the additional preconditioning with the single one. The I/R ratio was 25.4 +/- 8.5% in group G, 22.8 +/- 7.0% in group H, and 14.7 +/- 4.0% in group I (p = NS). Group D showed a higher I/R compared with groups G, A, and H (p < 0.01), and group I had a smaller I/R compared with groups A (p < 0.01) and D (p < 0.001). Cardioprotection after a first preconditioning declines gradually and is eventually lost. An additional preconditioning is always effective, and the longer the interval from the first preconditioning, the more potent is the effect.
本研究的目的是评估预处理中短期保护作用下降并最终丧失的方式，并确定在不同再灌注间隔进行第二次预处理的效果。将雄性兔子分为六组。在5分钟预处理后60、65、70、75和80分钟（A、B、C、D和E组）以及未进行预处理的对照组（F组）施加45分钟（持续）缺血，随后进行120分钟再灌注。A组的梗死与危险比值（I/R）为38.3±3.5%，B组为46.0±7.8%，C组为61.6±9.7%，D组为68.1±4.2%，E组为64.5±7.8%，F组为61.0±7.7%。与C、D、E和F组相比，A组的I/R较小（p<0.05）。在另一系列实验中，G、H和I组分别接受两次5分钟的预处理刺激，中间分别间隔45、60和75分钟的再灌注；在最后一次预处理后10分钟，动物接受45分钟缺血和120分钟再灌注。还将A组和D组（I/R比值较小和较大）纳入该方案，以比较额外预处理与单次预处理的效果。G组的I/R比值为25.4±8.5%，H组为22.8±7.0%，I组为14.7±4.0%（p=无显著性差异）。与G、A和H组相比，D组的I/R较高（p<0.01），与A组（p<0.01）和D组（p<0.001）相比，I组的I/R较小。第一次预处理后的心脏保护作用逐渐下降并最终丧失。额外的预处理总是有效的，并且与第一次预处理的间隔时间越长，效果越强。
