A new function of myocardial myoglobin

心肌肌红蛋白的新功能

• 批准号: 12670036
• 负责人: TAKAHASHI Eiji
• 金额: $ 2.24万
• 依托单位: Yamagata University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12670036/
• 关键词: heart; oxygen; mitochondrion; image processing; hypoxia; ischemia; cardiac hypertrophy; diffusion; ミオグロビン; 活性酸素; 再灌流

Using a high-resolution spectrophotometric imaging system, relationship between intracellular oxygen supply and mitochondrial oxidative metabolism was examined in isolated single cardiomyocytes of the rat.Specific questions were; whether intracellular diffusion of oxygen limits mitochondrial oxidative metabolism, 2. if so, how mitochondria deal with such heterogeneities of intracellular oxygen supply, and 3. what is the functional significance of cytosolic myoglobin. I found that cytosolic myoglobin certainly accelerates intracellular oxygen diffusion but diffusional oxygen supply may not always fully match the oxygen requirement of mitochondria particularly those located in the cell core. Thus, hypoxic core with metabolic inhibition (anoxic core) may be present in single cardiomyocytes with moderately elevated oxygen metabolism. I further demonstrated that this metabolic inhibition in the cell core is usually eliminated in mitochondria with intact respiratory control. Thus, in vivo cardiac myocytes can compensates for relatively slow intracellular oxygen diffusion.

使用高分辨率分光光度成像系统，细胞内氧供应和线粒体氧化代谢之间的关系进行了研究，在分离的单个心肌细胞的大鼠。具体的问题是;是否细胞内扩散的氧限制线粒体氧化代谢，2。如果是这样，线粒体如何处理这种细胞内氧供应的不均匀性，以及3.胞浆肌红蛋白的功能意义。我发现胞浆肌红蛋白确实加速了细胞内氧的扩散，但扩散氧的供应可能并不总是完全匹配线粒体的氧需求，特别是那些位于细胞核心的线粒体。因此，具有代谢抑制的缺氧核心（缺氧核心）可能存在于具有适度升高的氧代谢的单个心肌细胞中。我进一步证明，这种在细胞核心的代谢抑制通常是消除线粒体与完整的呼吸控制。因此，体内心肌细胞可以补偿相对缓慢的细胞内氧扩散。

项目成果

Takahashi E, Endoh H, Doi K: "Visualization of myoglobin facilitated mitochondrial O_2 delivery in a single isolated cardiomyocyte"Biophys J. 78. 3252-3259 (2000)

Takahashi E、Endoh H、Doi K：“肌红蛋白的可视化促进了单个分离心肌细胞中线粒体 O_2 的传递”Biophys J. 78. 3252-3259 (2000)

Takahashi E, Endoh H, Ishikawa M, Kishi M, Doi K: "Effect of myoglobin inactivation on intracellular gradients of NADH fluorescence at critical mitochondrial oxygen supply"Adv Exp Med Biol. (in press).

Takahashi E、Endoh H、Ishikawa M、Kishi M、Doi K：“肌红蛋白失活对关键线粒体供氧时 NADH 荧光细胞内梯度的影响”Adv Exp Med Biol。

Takahashi T, Saito H, Hiroi M, Doi K, Takahashi E: "Effects of aging on inositol 1,4,5-triphosphate-induced Ca^<2+> release in unfertilized mouse oocytes"Mol Reprod Dev. 55. 299-306 (2000)

Takahashi T、Saito H、Hiroi M、Doi K、Takahashi E：“衰老对未受精小鼠卵母细胞中肌醇 1,4,5-三磷酸诱导的 Ca^2 释放的影响”Mol Reprod Dev。

Takahashi E: "Visualization of myoglobin facilitated mitochondrial O_2 delivery in a single isolated cardiomyocyte."Biophys J. 78. 3252-3259 (2000)

Takahashi E：“肌红蛋白的可视化促进了单个分离心肌细胞中线粒体 O_2 的传递。”Biophys J. 78. 3252-3259 (2000)

Endoh H, Doi K, Takahashi E: "Improved cardiac contractile functions in hypoxia-reoxygenation in rats treated with low concentration Co^<2+>"Am J Physiol. 279. H2713-H2719 (2000)

Endoh H、Doi K、Takahashi E：“用低浓度 Co^<2 > 治疗的大鼠缺氧复氧过程中心脏收缩功能得到改善”Am J Physiol。