Inositol 1,4,5-trisphosphate: a possible chemical link in excitation-contraction coupling in muscle.
نویسندگان
چکیده
The role of inositol 1,4,5-trisphosphate (InsP3) in excitation-contraction coupling in skeletal muscle was investigated by several methods. The following results were obtained. InsP3 is released by electrical stimulation of muscles. Exogenous InsP3 releases calcium from skinned muscle fibers at relatively high doses under normal conditions but does so at very low concentrations when blockers of the InsP3 5-phosphatase are present. Blockers of InsP3 release are effective blockers of calcium transients elicited by electrical stimulation of muscle fibers. It is proposed that InsP3 acts as a chemical second messenger between transverse (T)-tubular membrane depolarization and calcium release from the sarcoplasmic reticulum in skeletal muscle.
منابع مشابه
Triads and transverse tubules isolated from skeletal muscle contain high levels of inositol 1,4,5-trisphosphate.
We measured the content of inositol 1,4,5-trisphosphate in sarcoplasmic reticulum, transverse tubules, and triads isolated from frog skeletal muscle, as well as in triads isolated from rabbit skeletal muscle. We found that acid extracts of both transverse tubules and triads contained significant amounts of inositol 1,4,5-trisphosphate, in the range of 300-400 pmol/mg of protein as determined by...
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عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 82 18 شماره
صفحات -
تاریخ انتشار 1985