丹曲林钠对大鼠体内快肌和慢肌的作用。

The action of dantrolene sodium on rat fast and slow muscle in vivo.

Leslie G C, Part N J

Br J Pharmacol. 1981 Apr;72(4):665-72. doi: 10.1111/j.1476-5381.1981.tb09147.x.

Abstract

Rats, anaesthetized with urethane, were injected intravenously with dantrolene sodium in a carrier solution of 5% mannitol taken to pH 10 with NaOH. This carrier solution itself was without effect on extrafusal muscle contraction. 2. Dantrolene sodium (5 mg/kg) had a greater depressant action on the twitch contraction of the fast extensor digitorum longus (EDL) muscle than on the slow soleus (SOL) muscle. The EDL twitch was depressed to 25.9% +/- 1.2% (mean + s.e. mean, n = 7) of control whereas the SOL twitch was depressed to 31.3% +/- 0.4% (n = 9). These values were significantly different at the P less than 0.001 level. 3. The twitch contraction time to peak was reduced by approximately 35% in both EDL and SOL by dantrolene sodium. However, the drug reduced the half relaxation time of SOL by approximately 30% but that of EDL was hardly affected. 4. The effect of dantrolene sodium on contractions elicited by repetitive stimulation was dependent upon the stimulation frequency. For the SOL muscle the greater depression was produced at a stimulation frequency of 25 Hz and for EDL at 75 Hz. The minimum of depression was produced for a full fused tetanus for both muscles. 5. The significance of these findings is discussed in terms of the action of dantrolene sodium on motor control in the intact animal.

摘要

用乌拉坦麻醉的大鼠，通过静脉注射用氢氧化钠将pH值调至10的5%甘露醇载体溶液中的丹曲林钠。该载体溶液本身对梭外肌收缩没有影响。2. 丹曲林钠（5毫克/千克）对快速趾长伸肌（EDL）的抽搐收缩的抑制作用比对慢比目鱼肌（SOL）的抑制作用更强。EDL抽搐被抑制至对照的25.9%±1.2%（平均值±标准误，n = 7），而SOL抽搐被抑制至31.3%±0.4%（n = 9）。这些值在P小于0.001水平时有显著差异。3. 丹曲林钠使EDL和SOL的抽搐收缩达到峰值的时间均缩短了约35%。然而，该药物使SOL的半松弛时间缩短了约30%，但对EDL的半松弛时间几乎没有影响。4. 丹曲林钠对重复刺激引起的收缩的影响取决于刺激频率。对于SOL肌肉，在25赫兹的刺激频率下产生的抑制作用更大，对于EDL肌肉，在75赫兹的刺激频率下产生的抑制作用更大。对于两种肌肉的完全融合强直收缩，产生的抑制作用最小。5. 根据丹曲林钠对完整动物运动控制的作用，讨论了这些发现的意义。