[冬眠地松鼠（黄鼠属）骨骼肌中肌球蛋白重链同工型组成的季节性变化]

[Seasonal changes in the isoform composition of the myosin heavy chains in skeletal muscles of hibernating ground squirrels Spermophilus undulatus].

作者信息

Lazareva M V, Trapeznikova K O, Vikhliantsev I M, Bobylev A G, Klimov A A, Podlubnaia Z A

出版信息

Biofizika. 2012 Nov-Dec;57(6):982-7.

Abstract

Seasonal changes of the isoform composition of myosin heavy chains in skeletal muscles (m. triceps, m. longissimus dorsi, m. soleus, m. gastrocnemius, m. vastus lateralis) of hibernating ground squirrels Spermophilus undulatus were studied. Functional properties of myosin (the actin-activated ATPase activity and its Ca(2+)-sensitivity in vitro) were also examined. It was observed that the content of slow myosin heavy chain I isoform increased and the content of fast IIx/d isoform decreased in muscles of torpid ground squirrels and animals which are active in autumn and winter. In muscles of these animals the content of N2A-titin isorfom decreased although the relative content of NT-titin isoform, observed in striated muscles of mammals in our previous experimental works, increased. Actin-activated ATPase activity and Ca(2+)-sensitivity of myosin isolated from skeletal muscles of torpid and interbout ground squirrels were found to reduce. The changes observed are discussed in the context of adaptation of skeletal muscles of ground squirrels to hibernation conditions.

摘要

研究了冬眠地松鼠（黄鼠）骨骼肌（肱三头肌、背最长肌、比目鱼肌、腓肠肌、股外侧肌）中肌球蛋白重链同工型组成的季节性变化。还检测了肌球蛋白的功能特性（肌动蛋白激活的ATP酶活性及其体外Ca(2+)敏感性）。观察到，在蛰伏的地松鼠以及在秋季和冬季活跃的动物的肌肉中，慢肌球蛋白重链I同工型的含量增加，快肌球蛋白重链IIx/d同工型的含量减少。在这些动物的肌肉中，N2A-肌联蛋白同工型的含量减少，尽管在我们之前的实验工作中在哺乳动物的横纹肌中观察到的NT-肌联蛋白同工型的相对含量增加。从蛰伏和非蛰伏期地松鼠的骨骼肌中分离出的肌球蛋白的肌动蛋白激活的ATP酶活性和Ca(2+)敏感性降低。在黄鼠骨骼肌适应冬眠条件的背景下讨论了观察到的这些变化。