Localisation and quantification of dehydrogenase activities in single muscle fibres of mdx gastrocnemius
Localisation and quantification of dehydrogenase activities in single muscle fibres of mdx gastrocnemius
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mdx 腓肠肌单肌纤维脱氢酶活性的定位和定量
DOI：
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发表时间：
1999
影响因子：
2.3
通讯作者：
T. Matsuzaki
中科院分区：
文献类型：
--
作者：
Y. Nakae;P. Stoward;M. Shono;T. Matsuzaki
摘要琥珀酸脱氢酶（SDH）和乳酸脱氢酶（LDH）的动力学测定在单肌纤维在腓肠肌的不固定部分的营养不良mdx小鼠（与X连锁遗传疾病缺乏细胞骨架蛋白，dystrophin）和年龄匹配的C57 BL/10对照小鼠。 使用定量凝胶基质膜技术和实时图像分析系统。在再生的mdx腓肠肌和相应的对照中观察到三种主要的纤维类型：具有高SDH和LDH初始反应速度和活性的小纤维（S），具有低活性的这些酶的大纤维（L）和具有中等酶活性的中等大小的纤维（I）。mdx和对照肌肉中的小和中间纤维分别表现出高和中等的肌膜下SDH和LDH活动归因于积累的线粒体。mdx肌纤维的肌浆（不包括肌膜下区）内酶反应初速度与对照肌纤维的比值，SDH为0.958（S）、1.09（I）和0.959（L），LDH为1.03（S）、1.06（I）和1.07（L）。一个参数a，LDH的扩散出肌肉切片在凝胶基质膜上孵育期间的措施，被发现是0.981和1.00在mdx和对照肌肉，分别。因此，再生mdx肌纤维和正常对照肌纤维之间的酶的活性和微环境没有显着差异。这些数据表明，肌营养不良蛋白缺乏mdx肌肉LDH与细胞骨架蛋白或SDH活动的线粒体，其数量和形态不同的mdx肌纤维相比，在正常对照组的相互作用没有影响。SDH和LDH活性也发现在线粒体聚集在两个纵向两极的每个中央核在再生mdx肌纤维。它们与肌浆中的活性成正比，不包括肌膜下区域。
Abstract The kinetics of succinate (SDH) and lactate (LDH) dehydrogenases were determined in single muscle fibres in unfixed sections of the gastrocnemius of dystrophic mdx mice (with an X-linked genetic disorder lacking a cytoskeletal protein, dystrophin) and age-matched C57BL/10 control mice. Quantitative gel substrate-film techniques and a real-time image analysis system were used. Three main fibre types were observed in regenerated mdx gastrocnemius and in corresponding controls: small fibres (S) with high SDH and LDH initial reaction velocities and activities, large fibres (L) with low activities of these dehydrogenases and intermediate-sized fibres (I) with intermediate enzyme activities. The small and intermediate fibres in both mdx and control muscles exhibited respectively high and moderate subsarcolemmal SDH and LDH activities attributable to accumulated mitochondria. The ratios of the initial velocities of the intrinsic enzyme reactions in the sarcoplasm, excluding the subsarcolemmal regions, of mdx muscle fibres compared to those in control fibres were 0.958 (S), 1.09 (I) and 0.959 (L) for SDH, and 1.03 (S), 1.06 (I) and 1.07 (L) for LDH. A parameter a, a measure of the diffusion of LDH out of muscle sections during incubation on gel substrate films, was found to be 0.981 and 1.00 in mdx and control muscles, respectively. Thus there are no significant differences in the activities and microenvironments of the enzymes between regenerated mdx muscle fibres and normal control muscle fibres. These data suggest that dystrophin deficiency in mdx muscles has no effects on the interactions of LDH with cytoskeletal proteins or on SDH activities in mitochondria whose number and morphology differ in mdx muscle fibres compared to those in normal controls. SDH and LDH activities were also found in the mitochondria clustered on two longitudinally directed poles of each central nucleus in regenerated mdx muscle fibres. They were proportional to the activities in the sarcoplasm excluding the subsarcolemmal regions.
DOI：
10.1073/pnas.96.3.1129
发表时间：
1999-02-02
影响因子：
11.1
作者：
Brooks, GA;Dubouchaud, H;Butz, CE
通讯作者：
Butz, CE