Changes in canine latissimus dorsi muscle during 24 wk of continuous electrical stimulation.
Changes in canine latissimus dorsi muscle during 24 wk of continuous electrical stimulation.
复制标题
连续电刺激 24 周期间犬背阔肌的变化。
DOI：
10.1152/jappl.1992.72.3.828
复制
发表时间：
1992
影响因子：
3.3
通讯作者：
H. Wellens
中科院分区：
文献类型：
--
作者：
C. Lucas;M. Havenith;F. H. van der Veen;J. Habets;T. van der Nagel;J. M. Schrijvers;O. Penn;H. Wellens
为了研究大型动物横纹肌对电刺激的功能、结构和生化适应性，研究犬背阔肌（LD）连续24周，不断增加脉冲脉冲次数（脉冲脉冲持续时间250 ms，脉冲脉冲频率30 Hz）。12周后的体内力测量显示，脉动，即中间刺激与峰值力振幅之比，从0.94 +/- 0.03显著降低到0.13 +/- 0.08 (SE; n = 8, P < 0.05)，表明收缩速度降低。力-频率关系的陡峭部分也移到了较低的频率。酶组化和免疫组化观察到纤维类型组成的显著变化，I型纤维从29.5 +/- 2.9增加到83 +/- 8% （SE; n = 8, P < 0.05）。在此期间，IIc/Ic型光纤的数量出现了短暂的上升（从3%到10%）。在受刺激的肌肉中，毛细血管/纤维比值由1.9 +/- 0.4增加到2.7 +/- 0.1 （P < 0.05）。线粒体体积也显著增加，特别是在纤维的外周部分。肌酸激酶和乳酸脱氢酶的活性在12周内显著下降。同时观察到乳酸脱氢酶同工酶模式向心脏组成的转变。刺激12周后没有发生额外的变化，表明犬LD肌肉的转化在此期间完成。
To study functional, structural, and biochemical adaptations to electrical stimulation of striated muscle in a large animal, the canine latissimus dorsi (LD) muscle was conditioned continuously for 24 wk with an increasing number of pulse bursts (burst duration 250 ms, burst frequency 30 Hz). Force measurements in vivo after 12 wk showed a significant decrease in the ripple, the ratio of interstimulus to peak force amplitude, from 0.94 +/- 0.03 to 0.13 +/- 0.08 (SE; n = 8, P less than 0.05), indicating reduction in contractile speed. Also the steep part of the force-frequency relation shifted to lower frequencies. A significant change in fiber-type composition was seen with both enzyme- and immunohistochemistry, manifested by an increase of type I fibers from 29.5 +/- 2.9 to 83 +/- 8% (SE; n = 8, P less than 0.05). During this period a transient rise in the number of type IIc/Ic fibers (from 3 to 10%) was seen. In the stimulated muscle, capillary-to-fiber ratio increased from 1.9 +/- 0.4 to 2.7 +/- 0.1 (P less than 0.05). A significant increase in mitochondrial volume was also seen, especially in the peripheral part of the fiber. Both creatine kinase and lactate dehydrogenase revealed a significant decline in activity within 12 wk. At the same time a shift in lactate dehydrogenase-isozyme pattern was observed toward the cardiac composition. No additional changes occurred after 12 wk of stimulation, indicating that conversion of the canine LD muscle was complete within this period.