Fukui Takehiko, Ishida Kazuyoshi, Mizukami Yoichi, Shiramoto Kiyotaka, Harada Hidenori, Yamashita Atsuo, Yamashita Satoshi, Matsumoto Mishiya
Department of Anesthesiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan.
Center for Gene Research, Yamaguchi University, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan.
J Anesth. 2018 Feb;32(1):3-14. doi: 10.1007/s00540-017-2420-5. Epub 2017 Nov 1.
This study aimed to determine the relative potency of direct ischemic preconditioning (DIPC) and remote ischemic preconditioning (RIPC) for protection against ischemic spinal cord injury in rabbits and to explore the mechanisms involved.
In experiment 1, we compared the neurological and histopathological outcomes of DIPC, kidney RIPC, and limb RIPC. The DIPC and kidney RIPC groups received two cycles of 5-min occlusion/15-min reperfusion of the abdominal aorta and left renal artery, respectively. The limb RIPC group received two cycles of 10-min occlusion/10-min reperfusion of the femoral arteries bilaterally. Thirty minutes after the conditioning ischemia, spinal cord ischemia was produced by occluding the abdominal aorta for 15 min. In experiments 2 and 3, we investigated whether pretreatment using a free-radical scavenger, dimethylthiourea (DMTU), an adenosine A receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), or a mitochondrial ATP-sensitive potassium channel antagonist, 5-hydroxydecanoate (5HD), could attenuate the protective effects of DIPC. In experiment 4, comprehensive analysis of phosphorylated proteins in the spinal cord was performed using a Proteome Profiler Array followed by immunoblotting to elucidate the signal pathway activated by DIPC.
In experiment 1, DIPC improved the neurological and histopathological outcomes, whereas kidney and limb RIPC had no protective effects. In experiments 2 and 3, strong protective effects of DIPC were reconfirmed but were not attenuated by DMTU, DPCPX, or 5HD. In experiment 4, DIPC induced phosphorylation of Akt2.
DIPC, but not kidney or limb RIPC, protected against ischemic spinal cord injury in rabbits. Akt2 might contribute to this protective effect.
本研究旨在确定直接缺血预处理（DIPC）和远程缺血预处理（RIPC）对兔脊髓缺血性损伤的相对保护效力，并探讨其相关机制。
在实验1中，我们比较了DIPC、肾脏RIPC和肢体RIPC的神经学和组织病理学结果。DIPC组和肾脏RIPC组分别接受两个周期的腹主动脉和左肾动脉5分钟闭塞/15分钟再灌注。肢体RIPC组接受双侧股动脉两个周期的10分钟闭塞/10分钟再灌注。预处理缺血30分钟后，通过闭塞腹主动脉15分钟造成脊髓缺血。在实验2和3中，我们研究了使用自由基清除剂二甲基硫脲（DMTU）、腺苷A受体拮抗剂8-环戊基-1,3-二丙基黄嘌呤（DPCPX）或线粒体ATP敏感性钾通道拮抗剂5-羟基癸酸（5HD）进行预处理是否会减弱DIPC的保护作用。在实验4中，使用蛋白质组分析阵列对脊髓中的磷酸化蛋白进行综合分析，随后进行免疫印迹以阐明DIPC激活的信号通路。
在实验1中，DIPC改善了神经学和组织病理学结果，而肾脏和肢体RIPC没有保护作用。在实验2和3中，再次证实了DIPC具有强大的保护作用，且未被DMTU、DPCPX或5HD减弱。在实验4中，DIPC诱导了Akt2的磷酸化。
DIPC而非肾脏或肢体RIPC可保护兔免受脊髓缺血性损伤。Akt2可能促成了这种保护作用。
