EVOLUTION OF SKELETAL-MUSCLE EXCITATION-CONTRACTION COUPLING AND THE APPEARANCE OF DIHYDROPYRIDINE-SENSITIVE INTRAMEMBRANE CHARGE MOVEMENT
EVOLUTION OF SKELETAL-MUSCLE EXCITATION-CONTRACTION COUPLING AND THE APPEARANCE OF DIHYDROPYRIDINE-SENSITIVE INTRAMEMBRANE CHARGE MOVEMENT
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DOI：
10.1098/rspb.1994.0026
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发表时间：
1994-02-22
影响因子：
4.7
通讯作者：
BROWN, ER
中科院分区：
文献类型：
--
作者：
INOUE, I;TSUTSUI, I;BROWN, ER
本文研究了低等脊索动物和无脊椎动物横纹肌纤维的兴奋-收缩偶联。在agnathan七鳃鳗，抽搐响应电刺激后不变的Ca 2+内流被阻断的另外的Co 2+。在检查的无脊椎动物（鳃口，Oikopleura，Doliatrium，Diphyes，Patinopecten和箭虫），Ca 2+流入是必要的，以引起抽搐。七鳃鳗肌纤维的全细胞电压钳显示，膜内电荷运动部分被5 μ M硝苯地平，二氢吡啶（DHP）衍生物。从Branchiostoma和Patinopecten的纤维中的电荷运动是不敏感的硝苯地平，虽然钙电流被5 μ M硝苯地平阻断75%。结果表明，脊椎动物型的E-C耦合之间的头索动物和无颌类，并伴随着出现的DHP敏感成分的膜内电荷运动。
Excitation-contraction (E-C) coupling was studied in the striated muscle fibres of lower chordates and invertebrates. In the agnathan Lampetra, twitches in response to electrical stimulation were unchanged after Ca2+ influx was blocked by the addition of Co2+. In the invertebrates examined (Branchiostoma, Oikopleura, Doliolum, Diphyes, Patinopecten and Sagitta), Ca2+ influx was necessary to cause a twitch. Whole-cell voltage clamp on muscle fibres of Lampetra revealed that intramembrane charge movement was partly blocked by 5 mu M nifedipine, a dihydropyridine (DHP) derivative. Charge movement in fibres from Branchiostoma and Patinopecten was insensitive to nifedipine, although the Ca2+ current was 75% blocked by 5 mu M nifedipine. The results suggest that the vertebrate type of E-C coupling was acquired between cephalochordates and agnathans, and was accompanied by the appearance of the DHP-sensitive component of intramembrane charge movement.