Caffier G, Kössler F, Ransch E, Küchler G
Acta Biol Med Ger. 1982;41(2-3):205-13.
Na-octanoate (2-10 mM) altered the characteristics of the isometric twitch of isolated frog skeletal muscles. The peak tension, the maximum rate of tension rose, the time to peak tension, and the half relaxation time decreased. The tetanus tension was reduced by the same amount in percent as a single isometric twitch so that no changes occurred in the twitch/tetanus relationship. The fusion frequency of tetanic contractions increased. The isotonic contractions had a reduced shortening period. The shortening velocity was not affected. The K+ induced contractures were diminished. The S-shaped curve which relates peak tension to potassium concentration was shifted to more positive potentials. The maximum contractile strength was not attained even by complete depolarization. 1-2 mM caffeine removed the octanoate effects described above. The contracture induced by 7.5 mM caffeine produced the same maximum tension as that obtained in Ringer's solution, but the contracture began later and the rise of tension was retarded. The tension development of glycerol-extracted muscles was not affected by octanoate. The results are consistent with the hypothesis that the octanoate-induced changes of muscle contraction are due to a reduced Ca++ release from cellular stores.
辛酸钠（2 - 10 mM）改变了离体青蛙骨骼肌等长收缩的特性。峰值张力、张力上升的最大速率、达到峰值张力的时间以及半松弛时间均降低。强直张力降低的百分比与单次等长收缩相同，因此收缩/强直关系未发生变化。强直收缩的融合频率增加。等张收缩的缩短期缩短。缩短速度不受影响。钾离子诱导的挛缩减弱。将峰值张力与钾离子浓度相关联的S形曲线向更正的电位偏移。即使完全去极化也未达到最大收缩强度。1 - 2 mM咖啡因消除了上述辛酸钠的作用。7.5 mM咖啡因诱导的挛缩产生的最大张力与林格氏液中获得的相同，但挛缩开始较晚且张力上升延迟。甘油提取的肌肉的张力发展不受辛酸钠的影响。这些结果与以下假设一致，即辛酸钠诱导的肌肉收缩变化是由于细胞内储存的钙离子释放减少所致。
