Entrikin R K, Abresch R T, Sharman R B, Larson D B, Levine N A
Muscle Nerve. 1987 May;10(4):293-8. doi: 10.1002/mus.880100403.
This report focuses on the myotonic (mto) mouse, an autosomal recessive neuromuscular mutant first described in 1982. Studies in vivo confirmed the presence of hindlimb rigidity during walking and typical myotonic electromyographic (EMG) discharges that persisted after nerve transection and complete neuromuscular blockade. Studies of the contractility of mto muscles in vitro revealed reduced peak isometric tetanic tension and greatly prolonged relaxation times. Tubocurarine did not affect tension parameters, but did antagonize the delayed relaxation in vitro. On the basis of EMG studies alone this mutant can accurately be described as myotonic. Reduction of the contractile abnormalities by tubocurarine in vitro, however, poses further questions regarding the nature of the disorder. Although the more familiar dystrophic mouse (dy/dy) has been termed "myotonic" by some, the new mto mutant differs from it in all aspects examined.
本报告聚焦于强直性肌营养不良（mto）小鼠，这是一种常染色体隐性神经肌肉突变体，于1982年首次被描述。体内研究证实，该小鼠在行走时存在后肢僵硬现象，并且在神经切断和完全神经肌肉阻滞之后，典型的强直性肌电图（EMG）放电依然持续。对mto肌肉体外收缩性的研究显示，其等长强直收缩峰值张力降低，舒张时间大幅延长。筒箭毒碱不影响张力参数，但可在体外拮抗延迟舒张。仅基于肌电图研究，该突变体可被准确描述为强直性的。然而，筒箭毒碱在体外减轻收缩异常的现象，引发了关于该病症本质的更多问题。尽管更为人熟知的营养不良性小鼠（dy/dy）被一些人称为“强直性的”，但新的mto突变体在所有已检测的方面都与之不同。
