Bradykinin limits infarction when administered as an adjunct to reperfusion in mouse heart: the role of PI3K, Akt and eNOS
Bradykinin limits infarction when administered as an adjunct to reperfusion in mouse heart: the role of PI3K, Akt and eNOS
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DOI：
10.1016/s0022-2828(02)00310-3
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发表时间：
2003-02-01
影响因子：
5
通讯作者：
Yellon, DM
中科院分区：
文献类型：
--
作者：
Bell, RM;Yellon, DM
生长因子引起的再灌注损伤的减轻最近与磷脂酰肌醇-3激酶（PI 3 K）和蛋白激酶B（Akt）的募集有关，这是一种也与缓激肽引起的eNOS磷酸化有关的途径。因此，我们假设，当作为再灌注的辅助药物时，缓激肽将限制梗死面积。使用缺血/再灌注损伤的离体灌流小鼠心脏模型，我们表明，再灌注时给予100 nmol/L缓激肽，可缩小梗死面积（32 +/- 2%至22 +/-2%，P < 0.01）。这种保护作用被PI 3 K抑制剂渥曼青霉素（100 nmol/l）的同时给药所消除，而单独的渥曼青霉素对梗死面积没有影响（分别为31 +/- 3%和30 +/-1%）。在eNOS敲除的心脏中，缓激肽没有保护作用（31.2%对32.2%），而一氧化氮供体S-亚硝基-N-乙酰青霉胺（SNAP）（1 μ mol/l）可以挽救敲除的心脏（17 +/-4%，P < 0.01）。使用蛋白质印迹分析，我们表明缓激肽给药导致Akt和eNOS快速、稳健的磷酸化，大于再灌注时在对照心脏中观察到的磷酸化（Akt/eNOS磷酸化：分别为68 +/- 7/122 +/- 29 Au对32 +/- 5/47 +/- 10 Au，P < 0.01）。这种Akt磷酸化模式在不存在eNOS的情况下被模拟，而Akt磷酸化则被渥曼青霉素抑制。外源性一氧化氮给药对Akt磷酸化没有影响。因此，我们证明，再灌注时给予外源性缓激肽可以限制梗死面积，同时伴随Akt和eNOS的快速磷酸化，并且这种保护作用取决于eNOS的存在。这些结果可能为研究急性心肌梗死后再灌注损伤的临床局限性开辟新的途径。(C)2003爱思唯尔科技有限公司。保留所有权利。
Attenuation of reperfusion injury by growth factors has recently been linked to recruitment of phosphatidylinositol-3 kinase (PI3K) and protein kinase B (Akt), a pathway also linked to the phosphorylation of eNOS by bradykinin. We, therefore, hypothesised that bradykinin would limit infarct size when given as an adjunct to reperfusion.Using an isolated perfused mouse heart model of ischaemia/reperfusion injury, we show that 100 nmol/I bradykinin, administered upon reperfusion, attenuates infarct size (32 +/- 2% to 22 +/- 2%, P < 0.01). This protection was abrogated by concomitant administration of the PI3K inhibitor, wortmannin (100 nmol/1), whereas wortmannin alone had no impact upon infarct size (31 +/- 3% and 30 +/- 1 %, respectively). In eNOS knockout hearts, bradykinin was not seen to be protective (31 2% versus 32 2%), yet knockout hearts could be rescued with the nitric oxide donor, S-nitroso-N-acetyl penicillamine (SNAP) (1 mumol/l) (17 +/- 4%, P < 0.01). Using western blot analysis, we show that bradykinin administration results in rapid, robust phosphorylation of both Akt and eNOS, greater than that seen in control hearts upon reperfusion (Akt/eNOS phosphorylation: 68 +/- 7/122 +/- 29 AU versus 32 +/- 5/47 +/- 10 AU respectively, P < 0.01). This pattern of Akt phosphorylation was mimicked in the absence of eNOS, whereas Akt phosphorylation was inhibited by wortmannin. Exogenous nitric oxide administration had no impact upon Akt phosphorylation.Therefore, we demonstrate that exogenous bradykinin, administered at reperfusion, limits infarct size with concomitant rapid phosphorylation of Akt and eNOS, and that this protection is dependent upon the presence of eNOS. These results may open new avenues for research into clinical limitation of reperfusion injury following acute myocardial infarction. (C) 2003 Elsevier Science Ltd. All rights reserved.