Basic study on cerebral vasospasm: Ca2+ movement during contraction-relaxation of isolated basilar arteries.
Basic study on cerebral vasospasm: Ca2+ movement during contraction-relaxation of isolated basilar arteries.
复制标题
脑血管痉挛的基础研究：离体基底动脉收缩-舒张过程中Ca2+的运动。
DOI：
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发表时间：
1979
影响因子：
1.9
通讯作者：
K. Hotta
中科院分区：
文献类型：
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作者：
T. Takagi;H. Fukuoka;H. Nagai;K. Hotta
为了建立脑血管痉挛的明确治疗方法，对脑动脉血管平滑肌的收缩机制进行了基础研究。牛基底动脉平滑肌细胞的超微结构检查揭示了两种类型的肌丝的存在，分别对应于粗丝和细丝。此外，还证实了表面膜内部存在内部膜系统。对基底动脉带机械活动的实验表明，K+ 诱导的收缩与肌细胞外部 Ca2+ 流入的大量增加有关。另一方面，5HT 在没有 Ca2+ 流入的情况下诱导张力。 Ca 拮抗剂（桂利嗪或维拉帕米）抑制高 K+ 诱导的收缩，而其对 5HT 诱导的收缩的抑制作用很小。这些事实表明 5HT 可以从细胞内储存位点释放 Ca。这里显示的结果表明，肌细胞中存在几种结合的 Ca，即： 1）松散的； 2) 与细胞膜外表面紧密结合的Ca； 3）Ca结合在细胞膜内表面； 4) Ca 储存在细胞内储存位点，例如肌浆网或线粒体。提示这种细胞内固定化Ca可能在脑动脉肌机械活动的调节中发挥重要作用。
To establish a definitive therapy for cerebral vasospasm, a basic study on the contractile mechanism of vascular smooth muscles of the cerebral artery was performed. Ultrastructural examination of smooth muscle cells in bovine basilar arteries revealed the existence of two types of myofilaments which correspond to thick and thin filaments. Also, the existence of an internal membrane system just inside of the surface membrane was confirmed. Experiments on the mechanical activity of basilar arterial strips showed that a K+ induced contraction was associated with a large increase of Ca2+ influx from outside of the muscle cell. On the other hand, 5HT induced tension without Ca2+ influx. A Ca antagonist (cinnarizine or verapamil) inhibited high K+ induced contractions, whereas its inhibitory effect on 5HT induced contraction was small. These facts suggest that 5HT can release Ca from intracellular store sites. The results shown here indicate that there are several kinds of bound Ca in the muscle cell, i.e.: 1) loosely; and 2) tightly bound Ca on the external surface of the cell membrane; 3) Ca bound in the internal surface of the cell membrane; and 4) Ca stored in the intracellular store sites, such as sarcoplasmic reticulum or mitochondria. It is suggested that such intracellularly immobilized Ca may play an important role in the regulation of mechanical activity of cerebral arterial muscle.