Saborido A, Molano F, Moro G, Megías A
Department of Biochemistry and Molecular Biology I, Faculty of Chemistry, Complutense University, Madrid, Spain.
Pflugers Arch. 1995 Jan;429(3):364-9. doi: 10.1007/BF00374151.
To examine the influence of exercise training on the expression of dihydropyridine (DHP)-sensitive Ca2+ channels in skeletal and cardiac muscle, we have determined DHP receptor levels by [3H]PN200-110-binding and immunoblot analysis in homogenates and microsomal fractions of slow- and fast-twitch muscles and heart from rats subjected to a 12-week programme of moderate endurance training. We found that exercise increases the amount of DHP receptor in homogenates of the slow-twitch soleus (42%) and the fast-twitch extensor digitorum longus (60%). Comparable increases in DHP receptor density with training were also observed in the microsomal fractions isolated from both skeletal muscles; these increases were not due to differences in the membrane composition of the microsomal fractions, since the relative proportion of specific enzyme markers was not affected by exercise training. Levels of DHP receptor were not modified in cardiac muscle as a result of the exercise programme. These data suggest an up-regulation of the DHP receptor in the skeletal muscle as a consequence of exercise training, which may play a role in the adaptation of skeletal muscle to increased contractile activity.
为了研究运动训练对骨骼肌和心肌中对二氢吡啶（DHP）敏感的Ca2+通道表达的影响，我们通过[3H]PN200-110结合以及免疫印迹分析，测定了经过12周中等强度耐力训练的大鼠的慢肌和快肌以及心脏的匀浆和微粒体部分中的DHP受体水平。我们发现，运动使慢肌比目鱼肌匀浆中的DHP受体量增加（42%），快肌趾长伸肌匀浆中的DHP受体量增加（60%）。在从这两种骨骼肌分离得到的微粒体部分中，也观察到随着训练DHP受体密度有类似增加；这些增加并非由于微粒体部分膜组成的差异，因为特定酶标志物的相对比例不受运动训练影响。运动训练并未改变心肌中的DHP受体水平。这些数据表明，运动训练可导致骨骼肌中DHP受体上调，这可能在骨骼肌适应增加的收缩活动中发挥作用。
