Analysis of human cultured myotubes responses mediated by ryanodine receptor 1
Analysis of human cultured myotubes responses mediated by ryanodine receptor 1
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DOI：
10.1177/0310057x1103900216
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发表时间：
2011-03-01
影响因子：
1.5
通讯作者：
Yuge, O.
中科院分区：
文献类型：
--
作者：
Kobayashi, M.;Mukaida, K.;Yuge, O.
恶性高热是由兰尼碱受体1型基因的常染色体显性突变引起的危及生命的疾病。在日本，通过钙诱导的钙释放试验来识别易患恶性高热的患者。我们研究了在人类培养的肌细胞的细胞内钙离子浓度和比较的敏感性肌管Ryanodine受体1型激活剂的基础上钙诱导的钙释放速率。我们评估了这种方法作为恶性低体温症易感性的鉴定试验的实用性。肌肉标本来自34个接受钙诱导的钙释放试验的个体。我们培养肌管从剩余的材料和监测细胞内钙浓度的变化后，暴露于兰尼碱受体1型激活剂咖啡因，氟烷和4-氯间甲酚通过测量呋喃-2荧光。我们确定了每个肌管中供试化合物的半数最大有效浓度（EC 50），并使用受试者工作特征曲线计算了截止点。根据钙诱导的钙释放速率，将17例患者分为加速组和非加速组。加速组咖啡因、氟烷和4-氯间甲酚的EC_（50）值显著低于非加速组（P < 0.001、P < 0.001和P < 0.001）。计算的EC 50值的截止点毛皮咖啡因，氟烷和4-CmC分别为3.62 mM，2.28 mM和197 μ M。在加速组的肌管中观察到对Ryanodine受体1型激活剂的敏感性增加。对人类培养的肌管进行的功能测试表明，其细胞内Ca 2+稳态的改变可能会识别恶性高热的易感性。
Malignant hyperthermia is a life-threatening condition caused by autosomal dominant mutations in the ryanodine receptor type 1 gene. Identifying patients predisposed to malignant hyperthermia is done through the Ca-induced Ca release test in Japan. We examined the intracellular calcium concentration in human cultured muscle cells and compared the sensitivity of myotubes to ryanodine receptor type 1 activators based on the Ca-induced Ca release rate. We assessed the utility of this method as an identifying test for predisposition to malignant hypothermia.Muscle specimens were obtained from 34 individuals undergoing the Ca-induced Ca release test. We cultured myotubes from residual material and monitored changes in intracellular calcium concentration after exposure to the ryanodine receptor type 1 activators caffeine, halothane and 4-chloro-m-cresol by measuring fura-2 fluorescence. We determined the half maximal effective concentrations (EC50) for the test compounds in each myotube and calculated cut-off points using receiver operating characteristic curves. Seventeen patients each were classified into the accelerated and non-accelerated groups based on their Ca-induced Ca release rate. The EC50 values for caffeine, halothane and 4-chloro-m-cresol of the accelerated group were significant lower than those of the non-accelerated group (P < 0.001, P < 0.001 and P < 0.001, respectively). The calculated cut-off points of EC50 values fur caffeine, halothane and 4-CmC were 3.62 mM, 2.28 mM and 197 mu M, respectively. An increased sensitivity to ryanodine receptor type 1 activators was seen in myotubes in the accelerated group. This functional test on human cultured myotubes indicates that the alteration of their intracellular Ca2+ homeostasis may identify the predisposition to malignant hyperthermia.