Rutschmann M, Dahlmann B, Reinauer H
Biochem J. 1984 Aug 1;221(3):645-50. doi: 10.1042/bj2210645.
By means of pyrophosphate electrophoresis the myosin isoenzyme pattern of two fast-twitch skeletal muscles (extensor digitorum longus, gastrocnemius) and one slow-twitch muscle (soleus) was investigated in control rats and was compared with that of rats 4 weeks after induction of diabetes mellitus by streptozotocin injection. In the fast-twitch muscles the isomyosin pattern consisting of FM1 (fast isomyosin 1), FM2 and FM3 was strongly affected by diabetes, resulting in an extensive loss of FM1 and a substantial decrease of FM2. These changes were also apparent when the light chains of the fast isomyosins were analysed by two-dimensional electrophoresis: LC3f (myosin light chain 3f) largely disappeared and LC2f was significantly diminished. In contrast, the isomyosin pattern in soleus muscle, consisting of SM1 (slow isomyosin 1) and SM2, was not affected by the diabetic state, and two-dimensional electrophoresis revealed a normal light-chain pattern of LC1sa, LC1sb and LC2s. These results indicate that the isomyosins of slow-twitch oxidative myofibres are more resistant to the hormonal and metabolic disorders during diabetes mellitus than are the isomyosins of fast-twitch fibres.
通过焦磷酸电泳，研究了对照大鼠的两块快肌（趾长伸肌、腓肠肌）和一块慢肌（比目鱼肌）的肌球蛋白同工酶模式，并将其与链脲佐菌素注射诱导糖尿病4周后的大鼠的肌球蛋白同工酶模式进行了比较。在快肌中，由FM1（快肌球蛋白1）、FM2和FM3组成的异肌球蛋白模式受到糖尿病的强烈影响，导致FM1大量丧失和FM2显著减少。当通过二维电泳分析快肌球蛋白的轻链时，这些变化也很明显：LC3f（肌球蛋白轻链3f）基本消失，LC2f显著减少。相比之下，比目鱼肌中由SM1（慢肌球蛋白1）和SM2组成的异肌球蛋白模式不受糖尿病状态的影响，二维电泳显示LC1sa、LC1sb和LC2s的轻链模式正常。这些结果表明，与快肌纤维的肌球蛋白相比，慢肌氧化肌纤维的肌球蛋白对糖尿病期间的激素和代谢紊乱更具抵抗力。
