Functional Expression of L-Type Cardiac Calcium Channels in Mammalian Cell in in vivo and in vitro by Use of Adenovirus.

利用腺病毒在体内和体外哺乳动物细胞中 L 型心脏钙通道的功能表达。

• 批准号: 09670049
• 负责人: ONO Katsushige
• 金额: $ 1.09万
• 依托单位: OITA MEDICAL UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09670049/
• 关键词: calcium channel; subconductance; alpha subunit; beta subunit; CHW Ccells; dihydropyridine; rabbit

(1) Formation of single channel subconductance is one of the unique characteristics of the L-type Ca^2^+ channel. The alpha, subunit exhibits a primary function of the channel, it remains uncertain whether alpha subunit alone is able to produce subconductance.(2) We tested this by studying single channel currents of cloned cardiac alpha subunit expressed in Chinese hamster fibroblast (CHW) cells, with/without coexpression of cardiac beta subunit.(3) The alpha, subunit exhibited four distinct levels of conductance (22.7, 14.3, 6.2 and 3.2 pS).(4) Coexpression of beta subunit significantly increased the number of openings in all four levels of conductance without changing the conductance values.(5) In whole-cell clamp study, both a1 channel and alpha, /beta channel yielded currents that peaked at -10 ms after voltage step. With coexpression of the beta subunit, the maximum peak currents were increased by -5 times and the fractional conductance curve were shifted to the negative potential by -10 mY.(6) In single channel study, with coexpression of the beta subunit,(1) The mean available time for channel openings was incresed,(2) The burst duration was marginally increased,(3) The mean first latency was shortened,(4) The mean open time was increased, yielding a second open state,(5) The mean closed times were unchanged.

(1)单通道亚电导的形成是L型Ca^2^+通道的独特特征之一。α亚基显示通道的主要功能，但α亚基单独是否能够产生亚电导仍不确定。(2)我们通过研究在中国仓鼠成纤维细胞（CHW）中表达的克隆的心脏α亚基的单通道电流来测试这一点，有/没有心脏β亚基的共表达。(3)α亚基表现出四个不同的电导水平（22.7、14.3、6.2和3.2pS）。(4)β亚基的共表达显着增加了所有四个水平的电导开口的数量，而不改变电导值。(5)在全细胞钳研究中，α 1通道和α 1/β通道均产生在电压阶跃后约10 ms达到峰值的电流。在β亚基共表达的情况下，最大峰电流增加约5倍，电导曲线向负电位移动约10 mY。(6)在单通道研究中，β亚基共表达时，（1）通道开放的平均可用时间增加，（2）爆发持续时间略有增加，（3）平均第一潜伏期缩短，（4）平均开放时间增加，产生第二开放状态，（5）平均关闭时间不变。

项目成果

N.Gondo, K.Ono, K.Mannen, A.Yatani, S.A.Green, M.Arita: "Four conductance levels of cloned cardiac L-type Ca^<2+> channel alpha_1 and alpha_1/beta subunits." FEBS Letters. 423. 86-92 (1998)

N.Gondo、K.Ono、K.Mannen、A.Yatani、S.A.Green、M.Arita：“克隆心脏 L 型 Ca^<2> 通道 alpha_1 和 alpha_1/beta 亚基的四个电导水平。”

T Wada, K.Ono, T.Hadama, Y Uchida, T.Shimada, M.Arita: "Detectection of Acute Cardiac Rejection by Analysis of Heart Rate Variability in Heterotopically Transplanted Rats." Journal of Heart and Lung Transplantation. (in press).

T Wada、K.Ono、T.Hadama、Y Uchida、T.Shimada、M.Arita：“通过分析异位移植大鼠的心率变异性来检测急性心脏排斥反应。”

K.Ono et al.: "Four conductance levels of cloned cardiac L-type Ca2+ channel a_1and_1/b subunists." FEBS Letters. 印刷中. (1998)

K.Ono 等人：“克隆心脏 L 型 Ca2+ 通道 a_1 和 1/b 亚单元的四种电导水平。” FEBS Letters（1998 年）。

K.Ono et al.: "Mechanissm of preservation of myocardial calcium channel function by pyruvate cardioplegic solution." J Lab Clin Med. 131. 136-145 (1998)

K.Ono 等人：“丙酮酸心脏停搏液保护心肌钙通道功能的机制。”

K.Ono et al.: "Four conductance levels of cloned cardiac L-type Ca^<2+> channel α_1 and α_1/β subunits." FEBS Letters. 423. 86-92 (1998)

K.Ono 等人：“克隆心脏 L 型 Ca^2+ 通道 α_1 和 α_1/β 亚基的四种电导水平。” FEBS Letters 423. 86-92 (1998)