Molecular Mechanism and its Clinical Significance of Abnormalities in Voltage-Sensitive Calcium Channel in the Diabetic Heart.

糖尿病心脏电压敏感钙通道异常的分子机制及其临床意义。

• 批准号: 01570357
• 负责人: KASHIWAGI Atsunori
• 金额: $ 1.41万
• 依托单位: Third Department of Medicine, Shiga University of Medical Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01570357/
• 关键词: Diabetes Mellitus,; Diabetic Myocardiopathy,; Protein Kinase C; Voltage-Sensitive Calcium Channel,; Calcium Channel Blocker; Intracellular Free Calcium,; Energy-Disperse X-Ray Microanalysis; Abnormal Regulation of Intracellular Calcium; 糖尿病性筋萎縮; ; Diabetes Mellitus,; Diabetic Myocardiopathy,; Protein Kinase C; Voltage-Sensitive Calcium Channel,; Calcium Channel Blocker; Intracellular Free Calcium,; Energy-Disperse X-Ray Microanalysis; Abnormal Regulation of Intracellular Calcium; 糖尿病性筋萎縮

Voltage operated calcium channel (VOCC) and intracellular calcium deposition were evaluated in cardiac muscle isolated from diabetic rats in order to identify calcium over-loading in diabetic cardiac myocytes. (1) Intramitochondrial calcium deposition in diabetic ventricular myocytes : collaboration with Dr Mizuhira of the Shionogi research laboratory, intracelluar calcium deposition was measured using the oxalate-pyroantimonate precipitation method , the microwave fixation method and energy-disperse X-ray microanalysis on electron microscope. Intramitochondrial calcium content in the diabetic group increased by 48% as compared with the control and the increase was marked in abnormally swollen mitochondria with disintegrated cristae which were marked in diabetic cardiac muscle. (2) Abnormalities in cardiac membrane VOCC in diabetes : Cardiac plasma membrane VOCC was measured using [3H]PN220-110, a dihydropyridine calcium channel blocker. An increase in the maximum binding site of [3H]P … More N200-110 was found in 6-wk-diabetic rats and the increase reached to 64% above the control in 10-wk-diabetic rats without any change in Kd for the binding. The [3H]PN200-110 binding to cardiac membrane fraction isolated from diabetic rats was less sensitive to verapamil effect. (3) Abnormalities in skeletal muscle membrane VOCC and intracellular calcium deposition : Using energy-disperse X-ray microanalysis, the increases in both intra-mitochondria and sarcoplasmic reticular calcium content were shown in soleus muscle obtained from diabetic rats. Furthermore, tissue calcium content which was measured by atomic absorption analysis also significantly increased in soleus muscle in diabetic rats as compared to the control. The maximum [3H]PN200-110 binding to skeletal muscle membrane fraction in the diabetic group significantly increased by 91% above the control without any change in the affinity of the binding. (4) The effect of calcium channel blocker on protein kinase C (PKC) activity in diabetic cardiac muscle : Both membrane-bound and soluble PKC activities in diabetic cardic muscle increased by 41 and 94% above the control, respectively. The increase in PKC in diabetic cardiac muscle was completely normalized by in vivo verapamil treatment. These results indicate that intracelluar calcium overloading in cardiac muscle may be associated with diabetic myocardiopathy. Less

在从糖尿病大鼠中分离出的心肌中评估了电压操作的钙通道（VOCC）和细胞内钙沉积，以鉴定糖尿病心肌细胞中的钙过载。 (1) Intramitochondrial calcium deposition in diabetic ventricular myocytes: collaboration with Dr Mizuhira of the Shionogi research laboratory, intracellular calcium deposition was measured using the oxalate-pyroantimonate precipitation method, the microwave fixation method and energy-disperse X-ray microanalysis on electronic microscope.与对照组相比，糖尿病组的糖内钙含量增加了48％，并且在绝对肿胀的线粒体中标记了cristae的绝对肿胀线粒体，并在糖尿病心脏肌肉中标记。 （2）使用[3H] PN220-110，一种二氢吡啶钙通道阻滞剂[3H] PN220-110测量心脏膜VOCC的异常：心脏质膜VOCC。在6周糖尿病大鼠中发现了[3H] p的最大结合位点的增加，而增加了N200-110，并且在10 wk糖尿病大鼠中，增加了对照组的64％，而KD的结合没有任何变化。 [3H] PN200-110与从糖尿病大鼠分离的心脏膜馏分结合对维拉帕米效应的敏感性不太敏感。 （3）骨骼肌膜VOCC和细胞内钙沉积的异常：使用能量分散X射线微分析，在糖尿病大鼠获得的soleus肌肉中显示了在糖尿病大鼠的肌肉中显示的肌内细胞内和肌肉网状钙含量的增加。此外，与对照组相比，通过原子吸收分析测量的组织钙含量也显着增加了糖尿病大鼠的比目鱼肌。糖尿病组中最大[3H] PN200-110与骨骼肌膜级分的结合显着增加了91％，高于对照组，而没有任何结合的亲和力任何变化。 （4）钙通道阻滞剂对糖尿病性心肌蛋白激酶C（PKC）活性的影响：膜结合和可溶性PKC在糖尿病心脏肌肉中的影响分别高于对照组的41％和94％。通过体内维拉帕米治疗，糖尿病心脏肌肉中PKC的增加完全归一化。这些结果表明，心肌内钙的过载可能与糖尿病心肌病有关。较少的