Lipicky R J, Bryant S H, Salmon J H
J Clin Invest. 1971 Oct;50(10):2091-103. doi: 10.1172/JCI106703.
In isolated fiber bundles of external intercostal muscle from each of 13 normal volunteers and each of 6 patients with myotonia congenita, some or all of the following were measured: concentrations of Na(+), K(+), and Cl(-), extracellular volume, water content, K(+) efflux, fiber size, fiber cable parameters, and fiber resting potentials. Muscle from patients with myotonia congenita differed significantly (0.001 <P< 0.025) with respect to the following mean values (myotonia congenita vs. normal): the membrane resistance was greater (5729 vs. 2619 omega.cm(2)), the internal resistivity was less (75.0 vs. 123.2 omega.cm), the water content was less (788.2 vs. 808.2 ml/kg wet weight), and the mean resting potential was greater (68 vs. 61 mv).NO SIGNIFICANT DIFFERENCES WERE FOUND WITH RESPECT TO THE FOLLOWING VARIABLES: K(+) content (73.5 vs. 66.7 mEq/kg wet weight) and the calculated intracellular K(+) concentration (215 vs. 191 mEq/liter fiber water), fiber capacitance (5.90 vs. 5.15 muf/cm(2)), Na(+) content (97.7 vs. 94.1 mEq/kg wet weight), Cl(-) content (79.0 vs. 74.7 mEq/kg wet weight), mannitol extracellular volume (45.1 vs. 46.6 cc/100 g wet weight), and K(+) efflux (23.2 vs. 21.5 moles x 10(-12) cm(-2).sec(-1)). These abnormalities of skeletal muscle in human myotonia congenita are like those of skeletal muscle in goats with hereditary myotonia. We tentatively conclude that a decreased Cl(-) permeability accounts for some of the abnormal electrical properties of skeletal muscle in myotonia congenita.
在13名正常志愿者和6名先天性肌强直患者的肋间外肌分离纤维束中，测量了以下部分或全部指标：Na⁺、K⁺和Cl⁻浓度、细胞外容积、含水量、K⁺外流、纤维大小、纤维电缆参数以及纤维静息电位。先天性肌强直患者的肌肉在以下平均值方面存在显著差异（0.001 <P< 0.025）（先天性肌强直与正常情况相比）：膜电阻更大（5729对2619Ω·cm²），内部电阻率更小（75.0对123.2Ω·cm），含水量更少（788.2对808.2 ml/kg湿重），平均静息电位更大（68对61 mV）。在以下变量方面未发现显著差异：K⁺含量（73.5对66.7 mEq/kg湿重）和计算得出的细胞内K⁺浓度（215对191 mEq/升纤维水）、纤维电容（5.90对5.15 μF/cm²）、Na⁺含量（97.7对94.1 mEq/kg湿重）、Cl⁻含量（79.0对74.7 mEq/kg湿重）、甘露醇细胞外容积（45.1对46.6 cc/100 g湿重）以及K⁺外流（23.2对21.5摩尔×10⁻¹² cm⁻²·秒⁻¹）。人类先天性肌强直中骨骼肌的这些异常与遗传性肌强直山羊的骨骼肌异常相似。我们初步得出结论，Cl⁻通透性降低是先天性肌强直中骨骼肌某些异常电特性的原因。
