Effects of physiological amounts of high- and low-rate chronic stimulation on fast-twitch muscle of the cat hindlimb. II. Endurance-related properties.
Effects of physiological amounts of high- and low-rate chronic stimulation on fast-twitch muscle of the cat hindlimb. II. Endurance-related properties.
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高速率和低速率慢性刺激的生理量对猫后肢快肌的影响。
DOI：
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发表时间：
1987
影响因子：
2.5
通讯作者：
O. Eerbeek
中科院分区：
文献类型：
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作者：
D. Kernell;Y. Donselaar;O. Eerbeek
1.长时间电刺激半脊髓化成年猫去传入后肢腓总神经。刺激量占每天总时间的0.5-5.5%，不同动物不同。对于本研究的某些方面，还使用了经受慢性刺激的“强直”模式的猫（通常覆盖总时间的50%; 10，16）。2.在全身麻醉下的终末急性实验中，在4或8周的长期刺激后进行，治疗的腓肌之一（m.腓骨长肌，PerL）用于测量抗收缩疲劳性。疲劳测试包括以40 Hz的频率进行0.33 s的运动神经刺激，每秒重复一次，持续4 min（6，7）。在此疲劳试验中，诱发复合棘波的肌肉记录肌电图（EMG）技术。在生理程序之后，取出Perl用于进一步的组织化学分析。在横切面，光密度的测量进行染色后的氧化酶，琥珀酸脱氢酶（核心SDH）的活性在中央区域的单纤维。3.将慢性刺激的Perl肌肉的结果与三种对照Perl肌肉进行比较：1）刺激的对侧，2）来自已去传入和半棘化但未受到慢性刺激的动物的手术侧的PerL肌肉，以及3）来自未处理的正常动物的PerL肌肉。4.覆盖大于或等于50%和5-5.5%的每日时间的刺激模式给出了抗疲劳性的显著改善。脉搏率似乎对这些影响不太重要。仅占每日总时间0.5%的模式没有引起超出正常肌肉的收缩耐力的增加。5.在对照肌肉的疲劳测试期间（见上文），复合EMG尖峰的幅度通常显示出显著下降。这种“EMG抑制”被所有现有的慢性刺激模式有效地抵消，包括0.5%模式。6.慢性刺激肌肉的纤维变得更加相似，彼此就其密度的核心SDH染色。然而，在每天总时间的0.5-5.5%期间处理的肌肉中，核心SDH染色的变化的程度和模式与慢性刺激的量和模式或由此产生的收缩耐力的程度无关。
1. Long-term electrical stimulation was given to the peroneal nerve of deafferented hindlimbs in hemispinalized adult cats. The amount of stimulation covered 0.5-5.5% of total time per day, different in different animals. For some aspects of the present study, use was also made of cats subjected to "tonic" patterns of chronic stimulation (typically covering 50% of total time; 10, 16). 2. In a terminal acute experiment under general anesthesia, performed after 4 or 8 wk of long-term stimulation, one of the treated peroneal muscles (m. peroneus longus, PerL) was used for measurements of the resistance to contractile fatigue. The fatigue test consisted of 0.33-s bursts of motor-nerve stimulation at 40 Hz, repeated once a second for 4 min (6, 7). During this fatigue test, the evoked compound spikes of the muscle were recorded by electromyographic (EMG) techniques. Following the physiological procedures, PerL was removed for further histochemical analysis. In transverse sections, measurements of optical density were made in central regions of single fibers after staining for the activity of an oxidative enzyme, succinate dehydrogenase (core SDH). 3. Findings from chronically stimulated PerL muscles were compared with three kinds of control PerL muscles: 1) those contralateral to the stimulated ones, 2) those from the operated side of animals that had been deafferented and hemispinalized but not subjected to chronic stimulation, and 3) those from untreated normal animals. 4. Stimulation patterns covering both greater than or equal to 50% and 5-5.5% of daily time gave a marked improvement of fatigue resistance. Pulse rate seemed of little importance for these effects. The pattern covering only 0.5% of total daily time caused no increase of contractile endurance beyond that of normal muscles. 5. During the fatigue test of a control muscle (see above), the amplitude of the compound EMG spikes typically showed a marked decline. This "EMG depression" was effectively counteracted by all the present patterns of chronic stimulation, including the 0.5% pattern. 6. Fibers of chronically stimulated muscles became more similar to each other with respect to their density of core SDH staining. However, among muscles treated during 0.5-5.5% of total daily time, the degree and pattern of change in core SDH staining was not related to the amount and pattern of chronic stimulation or to the resulting degree of contractile endurance.