Abstract
Striated muscle is well known to exist in either of two states-contraction or relaxation-under the regulation of Ca2+ concentration. Described here is a less well-known third, intermediate state induced under conditions of partial activation, known as SPOC (SPontaneous Oscillatory Contraction). This state is characterised by auto-oscillation between rapid-lengthening and slow-shortening phases. Notably, SPOC occurs in skinned muscle fibres and is therefore not the result of fluctuating Ca2+ levels, but is rather an intrinsic and fundamental phenomenon of the actomyosin motor. Summarised in this review are the experimental data on SPOC and its fundamental mechanism. SPOC presents a novel technique for studying independent communication and coordination between sarcomeres. In cardiac muscle, this auto-oscillatory property may work in concert with electro-chemical signalling to coordinate the heartbeat. Further, SPOC may represent a new way of demonstrating functional defects of sarcomeres in human heart failure.
Original language | English |
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Pages (from-to) | 53-62 |
Number of pages | 10 |
Journal | Biophysical Reviews |
Volume | 3 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2011 |
Keywords
- Auto-oscillation
- Cardiac muscle
- Sarcomere
- Skeletal muscle
- SPOC
ASJC Scopus subject areas
- Biophysics
- Molecular Biology
- Structural Biology