Elucidation of molecular biological mechanism of Ischemic preconditioning-northern blot analysis of m-RNA in ATP sensitive potassium channel

阐明缺血预适应的分子生物学机制——ATP敏感钾通道mRNA的northern blot分析

• 批准号: 09671380
• 负责人: KU Kwansong
• 金额: $ 0.32万
• 依托单位: Kinki University School of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09671380/
• 关键词: ischemic preconditioning; ATP-sensitive K+ channel; rat SUR-2; northern blot; rat heart; ラット; K^+-ATP channel; Ischemic preconditioning; rat

Preconditioning the heart with single of multiple brief periods of ischemia and reperfusion makes the heart very resistant to a subsequent ischemic insult. The phenomenon of myocardial preconditioning has now been confirmed in animals and may also exist in humans. However, no study has confirmed the molecular biological mechanism of ischemic preconditioning. ATP-sensitive K+ channel has been reported to be one of the mechanisms of ischemic preconditioning. However, there is no report that has verified molecular biological mechanisms of ischemic preconditioning. Two subunits have reported as ATP-sensitive K+ channels. One is rat SUR-2 and another is mouse kir 6.2. In the present study, we investigated whether ischemic preconditioning is mediated by SUR-2 using northern blot analysis.Materials and MethodsIschemic preconditioned rat hearts were divided to following six groups : group 1, no preconditioned control; group2, 15 min of reperfusion following 2.5 min of ischemia ; group3, 2 cycles of group2 ; group4, 15 min of reperfusion follwing 5 min of ischemia ; group5, 2 cycles of group4 ; group6, 15min of sreperfusion following 10 min of ischemia. Northern blot analysis were performed using predconditioned left ventricular muscle in each group.Results and CommentsIn the present study, SUR-2m-RNA was absent in isolated ischemic preconditioned rat hearts. The present results indicate that ischemic preconditioning may not be mediated by ATP-sensitive K+ channels, However, ATP-sensitive K+ channels may be a complex composed of at least two subunits, rat SUR-s and mouse kir 6.2 Neither subunit alone can produce K+ channel activity, and the therefore, further study should be conducted by using a complex composed of two subunits, rat SUR-2 and mouse kir 6.2 to confirm that ischemic preconditioning is not mediated by ATP-sensitive K+ channels.

用多个短暂的缺血和再灌注期中的一个对心脏进行预适应，使心脏对随后的缺血性损伤具有很强的抵抗力。心肌预适应的现象现已在动物身上得到证实，在人类中也可能存在。然而，目前尚无研究证实缺血预适应的分子生物学机制。ATP敏感性K+通道被认为是缺血预适应的机制之一。然而，目前尚无研究证实缺血预适应的分子生物学机制。有两个亚基被报道为ATP敏感的K+通道。一种是大鼠SUR-2，另一种是小鼠KIR 6.2。本研究采用Northern印迹杂交的方法，探讨了缺血预适应是否由SUR-2介导。材料与方法将大鼠缺血预适应分为6组：1组，无预适应对照组；2组，缺血2.5分钟后再灌流15分钟；3组，2个循环；4组，缺血5分钟后再灌流15分钟；5组，4组2个循环；6组，缺血10分钟后再灌流15分钟。结果与备注在本研究中，缺血预适应大鼠离体心组织中不存在SuR-2m-RNA。结果提示，缺血预适应可能不是由三磷酸腺苷敏感的K+通道介导的，而三磷酸腺苷敏感的钾通道可能是由至少两个亚基组成的复合体，大鼠苏-S和小鼠KIR 6.2都不能单独产生K+通道活动，因此，需要用大鼠SuR-2和小鼠KIR 6.2两个亚单位组成的复合体进行进一步的研究，以证实缺血预适应不是由三磷酸腺苷敏感的钾通道介导的。

项目成果

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