EFFECTS OF LACTIC-ACID ACCUMULATION AND ATP DECREASE ON MUSCLE TENSION AND RELAXATION
EFFECTS OF LACTIC-ACID ACCUMULATION AND ATP DECREASE ON MUSCLE TENSION AND RELAXATION
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DOI：
10.1152/ajpcell.1981.240.3.c121
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发表时间：
1981-01-01
影响因子：
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通讯作者：
HULTMAN, E
中科院分区：
文献类型：
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作者：
SAHLIN, K;EDSTROM, L;HULTMAN, E
研究了乳酸蓄积对等长收缩的最大张力和松弛速率的影响。在无氧条件下，以2/S的频率电刺激大鼠的指长伸肌。与用碘乙酸(IAA)阻断糖酵解的肌肉进行比较。刺激未中毒的肌肉3min，张力降低到50%，松弛时间增加到初始值的250%。乳酸增加了15倍。肌肉pH值由7.10降至6.76。刺激IAA中毒的肌肉1min可使张力降低至50%，但不增加松弛时间。刺激IAA中毒的肌肉，肌肉中的ATP和腺嘌呤核苷酸总量显著下降(约50%)。未中毒的肌肉中只有很小的下降(10%-15%)。未中毒肌肉张力下降明显与肌肉pH降低和ADP升高密切相关，而与ATP含量无关。松弛速度减慢明显与肌肉pH的降低密切相关，而与肌肉中的三磷酸腺苷或磷酸肌酸含量无关。
The effect of lactic acid accumulation on peak tension and relaxation rate of the isometric twitch was studied. Isolated extensor digitorum longus muscle from rat was stimulated electrically at a frequency of 2/s under anaerobic conditions. Comparison was made with muscles in which glycolysis was blocked with iodoacetic acid (IAA). Stimulation of unpoisoned muscles for 3 min decreased tension to 50% and increased relaxation time to 250% of the initial value. Lactate increased 15-fold. Muscle pH decreased from 7.10-6.76. Stimulation of IAA-poisoned muscles for 1 min decreased tension to 50% but did not increase the relaxation time. Stimulation of IAA-poisoned muscle resulted in a pronounced decrease (about 50%) of the ATP and total adenine nucleotide content in muscle. Only a small decrease (10-15%) occurred in unpoisoned muscle. Tension decline in unpoisoned muscle apparently is closely related to decrease in muscle pH and increase in ADP but not to ATP content. Slowing of relaxation rate apparently is closely related to decrease in muscle pH but not to muscle content of ATP or creatine phosphate.