Centre de Recherche Pierre Fabre, 17 Av. Jean Moulin, 81106 Castres, France.
Physiol Res. 2009;58(5):635-643. doi: 10.33549/physiolres.931596. Epub 2008 Nov 4.
The goal of the study was to determine whether postconditioning protects against different ischemia durations in the rabbit. Rabbits were assigned to a 20-, 25-, 45- or 60-min coronary occlusion followed by 24-h of reperfusion. Rabbits received no further intervention (control) or were postconditioned with four cycles of 30-s occlusion and 30-s reperfusion after myocardial infarction. Plasma levels of troponin I were quantified throughout reperfusion. In control conditions, infarct sizes (% area at risk using triphenyltetrazolium chloride) after 20, 25, 45 and 60 min of coronary occlusions were 23+/-3, 51+/-4, 70+/-3 and 81+/-3 %, respectively. With 20 and 25 min occlusion, postconditioning reduced infarct size by 43+/-10 and 73+/-21 %, respectively. On the other hand, with 45 or 60 min occlusion, postconditioning had no significant effects on infarct size (61+/-3 and 80+/-2 % of area at risk). Preconditioning protocol was performed with 25- and 60-min coronary occlusion. As expected, preconditioning significantly reduced infarct size. In conclusion, in the rabbit, the cardioprotection afforded by postconditioning is limited to less than 45 min coronary occlusion.
本研究旨在确定后处理是否能预防不同持续时间的兔心肌缺血。兔子被分配到 20 分钟、25 分钟、45 分钟或 60 分钟的冠状动脉闭塞，然后进行 24 小时再灌注。兔子未接受进一步干预（对照组）或在心肌梗死后接受 4 个 30 秒闭塞和 30 秒再灌注的后处理循环。在整个再灌注过程中定量检测肌钙蛋白 I 的血浆水平。在对照组中，20、25、45 和 60 分钟冠状动脉闭塞后的梗塞面积（氯化三苯基四氮唑法测定的危险区面积百分比）分别为 23+/-3%、51+/-4%、70+/-3%和 81+/-3%。20 分钟和 25 分钟闭塞时，后处理分别减少了 43+/-10%和 73+/-21%的梗塞面积。另一方面，在 45 分钟或 60 分钟闭塞时，后处理对梗塞面积没有显著影响（危险区面积的 61+/-3%和 80+/-2%）。采用 25 分钟和 60 分钟的冠状动脉闭塞进行预处理方案。如预期的那样，预处理显著减少了梗塞面积。总之，在兔中，后处理提供的心脏保护仅限于冠状动脉闭塞时间少于 45 分钟。
