López J R, Briceño L E, Cordovez G, Sánchez V, Linares N
Centro de Biofisica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
Gen Physiol Biophys. 1989 Apr;8(2):91-8.
Carnitine is required for the transport of activated long chain fatty acids through the mitochondrial inner membrane. We measured the intracellular free calcium concentration [( Ca2+]i) by means of a calcium selective microelectrode in skeletal muscle biopsies obtained from nine patients in which myopathic carnitine deficiency (MCD) was diagnosed, and from six subjects with no evidence of neuromuscular disease. Intact intercostal muscle bundles were dissected and then split for electron microscopic studies and electrophysiological measurements. The [Ca2+]i in muscle fibers from MCD patients was 0.46 +/- 0.02 mumol.l-1 (mean +/- SEM) and 0.10 +/- 0.01 mumol.l-1 in control subjects. At the electron microscopic level, the predominant abnormality was the presence of lipid vacuoles between the myofibrils. These results show that in patients with myopathic carnitine deficiency there is a significant increase in the resting myoplasmic calcium concentration which might be related to a malfunction of some mechanisms responsible for the homeostasis of intracellular calcium.
肉碱是活化的长链脂肪酸穿过线粒体内膜所必需的。我们通过钙选择性微电极测量了9例被诊断为肌病性肉碱缺乏症（MCD）患者以及6例无神经肌肉疾病证据的受试者的骨骼肌活检样本中的细胞内游离钙浓度[（Ca2+）i]。完整的肋间肌束被解剖，然后分开用于电子显微镜研究和电生理测量。MCD患者肌肉纤维中的[Ca2+]i为0.46±0.02μmol·l-1（平均值±标准误），对照组受试者为0.10±0.01μmol·l-1。在电子显微镜水平上，主要异常是肌原纤维之间存在脂质空泡。这些结果表明，在肌病性肉碱缺乏症患者中，静息肌浆钙浓度显著升高，这可能与负责细胞内钙稳态的某些机制功能失调有关。
