Obame Fatou Nsoure, Plin-Mercier Catherine, Assaly Rana, Zini Roland, Dubois-Randé Jean Luc, Berdeaux Alain, Morin Didier
INSERM U 841, F-94010 Créteil, France.
J Pharmacol Exp Ther. 2008 Jul;326(1):252-8. doi: 10.1124/jpet.108.138008. Epub 2008 Apr 23.
Morphine has been shown to protect the myocardium against ischemia-reperfusion injury through inhibition of glycogen synthase kinase-3beta (GSK-3beta). Given that GSK-3beta is known to modulate the mitochondrial permeability transition pore (mPTP), we investigated the role of mPTP in the cardioprotective effect of morphine and the GSK-3beta inhibitor SB216763 [SB; 3-(2,4-dichlorophenyl)-4(1-methyl-1H-indol-3-yl)-1H-pyrrole-2,5-dione] during ischemia-reperfusion. Both morphine (0.3 mg/kg) and SB (0.6 mg/kg) reduced infarct size in a model of regional myocardial ischemia-reperfusion in rats (13 +/- 1 and 14 +/- 3% of the area at risk versus 33 +/- 4% in controls; p < 0.05). Morphine and SB protected the ischemic myocardium against Ca(2+)-induced mPTP opening as demonstrated by the increased capacity of mitochondria to retain Ca(2+) when they were isolated from the ischemic zone 10 min after the onset of reperfusion (59 +/- 8 and 66 +/- 3 versus 29.5 +/- 6 nmol Ca(2+)/mg x protein, respectively; p < 0.05). This was associated with a restoration of mitochondrial oxidative phosphorylation parameters. In isolated adult rat cardiomyocytes subjected to anoxia-reoxygenation, morphine (2 microM), SB (3 microM), and the direct mPTP inhibitor cyclosporine A (3 microM) delayed mPTP opening as assessed by the calcein loading Co(2+)-quenching technique. This was accompanied by an increase in cell survival as measured by nuclear staining with propidium iodide. These in vitro effects of morphine on inhibition of mPTP opening during anoxia-reoxygenation were suppressed by the phosphatidylinositol 3-kinase (PI3-kinase) inhibitor wortmannin (0.1 microM). These data indicate that the infarct-limiting effect of morphine and SB is linked by a cause-effect relationship, which leads to an increased mitochondrial resistance and inhibition of mPTP opening through the PI3-kinase pathway and subsequent inactivation of GSK-3beta.
吗啡已被证明可通过抑制糖原合酶激酶-3β（GSK-3β）来保护心肌免受缺血-再灌注损伤。鉴于已知GSK-3β可调节线粒体通透性转换孔（mPTP），我们研究了mPTP在吗啡和GSK-3β抑制剂SB216763 [SB；3-(2,4-二氯苯基)-4(1-甲基-1H-吲哚-3-基)-1H-吡咯-2,5-二酮] 对缺血-再灌注期间的心脏保护作用中的作用。吗啡（0.3 mg/kg）和SB（0.6 mg/kg）均能减小大鼠局部心肌缺血-再灌注模型中的梗死面积（梗死面积占危险区域的比例分别为13±1%和14±3%，而对照组为33±4%；p<0.05）。吗啡和SB可保护缺血心肌免受Ca(2+)诱导的mPTP开放，这可通过再灌注开始10分钟后从缺血区分离出线粒体时其保留Ca(2+)的能力增强来证明（分别为59±8和66±3，而对照组为29.5±6 nmol Ca(2+)/mg x蛋白；p<0.05）。这与线粒体氧化磷酸化参数的恢复有关。在经受缺氧-复氧的成年大鼠分离心肌细胞中，吗啡（2 microM）、SB（3 microM）和直接mPTP抑制剂环孢素A（3 microM）通过钙黄绿素负载Co(2+)淬灭技术评估，延迟了mPTP的开放。这伴随着用碘化丙啶进行核染色测量的细胞存活率增加。吗啡在缺氧-复氧期间对mPTP开放的体外抑制作用被磷脂酰肌醇3-激酶（PI3-激酶）抑制剂渥曼青霉素（0.1 microM）所抑制。这些数据表明，吗啡和SB的梗死限制作用通过因果关系相联系，这导致线粒体抗性增加，并通过PI3-激酶途径抑制mPTP开放以及随后使GSK-3β失活。
