Yamashita K, Yoshioka T
Department of Physiology, St. Marianna University School of Medicine, Kanagawa, Japan.
J Muscle Res Cell Motil. 1991 Feb;12(1):37-44. doi: 10.1007/BF01781172.
Creatine kinase (CK) isoenzyme compositions of different types of single muscle fibres dissected from soleus (SOL) and extensor digitorum longus (EDL) muscles from rats were examined. CK isoenzymes were separated into cytoplasmic (CK-MM, CK-MB, CK-BB) (muscle, brain and hybrid types, respectively) and mitochondrial (m-CK) isoenzymes. Total CK and CK-MM activities showed the highest activities in fast-twitch glycolytic fibres (FG), lower in fast-twitch oxidative glycolytic (FOG) and the lowest in slow-twitch oxidative (SO) fibres. Conversely, the activity of m-CK was highest in SO, lowest in FG and intermediate in FOG fibres. The activity of CK-MB was highest in SO and lower in FOG and FG fibres. However, the activities of total CK and CK isoenzymes in a single muscle fibre type were not distinguishable from those of another type, and the profiles of CK isoenzyme compositions from the same type of single muscle fibres overlapped over a considerable range. The relationships between the four CK isoenzymes activities in single muscle fibres of different types were not similar. These results suggest that CK isoenzymes of single muscle fibres of different types play different roles in intracellular energy metabolism. Therefore, it is supposed that the CK isoenzyme compositions of single muscle fibres are suitable for their contractive and metabolic properties.
对从大鼠比目鱼肌（SOL）和趾长伸肌（EDL）中分离出的不同类型单根肌纤维的肌酸激酶（CK）同工酶组成进行了检测。CK同工酶被分离为细胞质同工酶（CK-MM、CK-MB、CK-BB）（分别为肌肉型、脑型和杂交型）和线粒体同工酶（m-CK）。总CK和CK-MM活性在快肌糖酵解纤维（FG）中最高，在快肌氧化糖酵解纤维（FOG）中较低，在慢肌氧化纤维（SO）中最低。相反，m-CK活性在SO纤维中最高，在FG纤维中最低，在FOG纤维中处于中间水平。CK-MB活性在SO纤维中最高，在FOG和FG纤维中较低。然而，单根肌纤维类型中的总CK和CK同工酶活性与其他类型之间没有差异，并且来自同一类型单根肌纤维的CK同工酶组成谱在相当大的范围内重叠。不同类型单根肌纤维中四种CK同工酶活性之间的关系并不相似。这些结果表明，不同类型单根肌纤维的CK同工酶在细胞内能量代谢中发挥不同作用。因此，可以推测单根肌纤维的CK同工酶组成适合其收缩和代谢特性。
