Maintenance for the positive inotropic effect in ischemic myocardial mitochondria and the development of new cardiac drug.

缺血心肌线粒体正性肌力作用的维持及新型强心药的开发。

• 批准号: 10672160
• 负责人: HOTTA Yoshihiro
• 金额: $ 2.05万
• 依托单位: Aichi Medical 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: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10672160/
• 关键词: Ischemia-reperfusion injury; ^<31>P-NMR; Fluorometry; EPR; Myocardial mitochondria; eNOS; Na-H exchange inhibitor; No-releasing drug; c(e)NOS; 虚血再灌流; 左室内圧(LVDP); NMR; fluorometry; ESR; ミトコンドリア; NOS; NO・ラジカル

Cardiac mitochondria are recognized to play an essential role in the pumping action of the heart. Mitochondria (about 30% volume) and heart muscle cells form an intimate symbiotic relationship the basic myocardial functions of which are maintenance via energy production/utilization and ion transport mechanisms. Therefore, we used ^<31>P-NMR and fluorometry to measure energy currency-related substances of ALP, PCr etc and various ions of H^+ Ca^<2+>, Na^+ in mitochondria. In 1998, we found that the protective effects of Na-H exchange inhibitor against ischemia/reperfusion injury are due in part to the Ca^<2+>-paradox at the mitochondrial level. The elevation of mitochondrial pH by the perfusate containing Na^+ or K^+ indicate the existence of antiport mechanisms (Na-H, K-H) between protons an these monovalent cations in the mitochondrial membrane. Matrix Ca^<2+1> in mitochondria preloaded with abnormally high Ca^<2+> were elevated by reperfusion of either with physiological concentratio … More n of Ca^<2+> or acidified perfusate of pH 6.5. This finding will interpret the Ca^<2+>-paradox at mitochondria level. In 1999, we concluded that eNOS exits in mitochondria, and that NO may play an important protective role against reperfusion cardiac injury after ischemia, by inhibiting the Ca^<2+> influx into mitochondria which are otherwise damaged by O_2^-. The production of reactive oxygen species and NO in isolated mitochondria was detected by EPR.Pretreatment with SNAP or NOC5, which spontaneously generate NO, completely inhibited the mitochondrial Ca^<2+> (Cam) uptake. The agents that inhibit Cam influx improve contractility even in Langendorff preparations after ischemia. Therefore, NO exogenously supplied by NO donor (FK409) was responsible for the cardioprotective action, presumably by acting directly as an oxygen radical scavenger during reperfusion. Antioxidant effects of 5HT derivatives from safflower or 5HT_<2A>-blocker increasing the NO basal level might play an important role in ischemia-reperfusion injury hearts in close relation with NO. Less

心肌线粒体被认为在心脏的泵送活动中起着重要的作用。线粒体(约30%的体积)与心肌细胞形成亲密的共生关系，其基本功能是通过能量产生/利用和离子转运机制维持心肌功能。因此，我们用~(31)&gt；P-核磁共振和荧光分光光度法对线粒体中的碱性磷酸酶、聚合酶链式反应等与能量流通有关的物质和H~(2+)、Ca~(2+)、Na~+进行了测定。1998年，我们发现Na-H交换抑制剂对缺血/再灌注损伤的保护作用部分归因于线粒体水平上的钙离子悖论。含Na~+或K~+的灌流液使线粒体膜pH升高，提示线粒体膜上质子与这些单价阳离子之间存在反向转运机制(Na-H，K-H)。生理浓度的…再灌流可使预先负载异常高钙的线粒体基质钙升高更多的钙离子或pH 6.5的酸化灌流液。这一发现将在线粒体水平上解释钙离子悖论。1999年，我们认为内皮型一氧化氮合酶存在于线粒体中，NO可能通过抑制线粒体内钙离子内流，对缺血再灌注心肌损伤起到重要的保护作用。自发产生NO的SNAP或NOC5可完全抑制线粒体钙摄取(CaM)。抑制CaM内流的药物可改善缺血后的兰登多夫制剂的收缩性能。因此，由NO供体(FK409)提供的外源性NO可能通过在再灌流期间直接作为氧自由基清除剂而起到心脏保护作用。红花5-羟色胺衍生物或5-羟色胺受体阻滞剂提高NO基础水平可能在心肌缺血再灌注损伤中起重要作用，与NO密切相关。较少

项目成果

Cao Y. et al.: "Protective effects of FK409, a nevel NO donor, against postischemic myocardial dysfunction in guinea-pig hearts."The Japanese Journal of Pharmacology. (発表予定). 296 (2000)

Cao Y.等人：“FK409（一种新的NO供体）对豚鼠心脏缺血后心肌功能障碍的保护作用”，《日本药理学杂志》（待出版）296（待出版）。

Hotta,Y. et al.: "Protective role of nitric oxide synthase in myocardial mitochondria against ischemia-reperfusion injury in guinea pig."Jpn.J.Pharmacol.. 79. 175 (1999)

堀田，Y.

Hotta Y. et al: "Protective role of nitric oxide synthase against ischemia-reperfusion injury in guinea pig myocardial mitochondria"Eur J Pharmacol.. 380. 37-48 (1999)

Hotta Y.等人：“一氧化氮合酶对豚鼠心肌线粒体缺血再灌注损伤的保护作用”Eur J Pharmacol.. 380. 37-48 (1999)

Yajima M. et al.: "Effect of sodium nitroprusside in rested state contraction of guinea-pig papillary muscle"Jpn.J.Pharmacol. 85. 81P (2001)

Yajima M.等人：“硝普钠对豚鼠乳头肌静息状态收缩的影响”Jpn.J.Pharmacol。

Liu W. et al.: "4-hydroxynonenal induces a cellular redox status-related activation of the caspase cascade for apoptotic cell death."J Cell Sci.. 113. 635-641 (2000)

Liu W. 等人：“4-羟基壬烯醛诱导细胞氧化还原状态相关的半胱天冬酶级联激活，导致细胞凋亡。”J Cell Sci.. 113. 635-641 (2000)