The Series Elasticity of Active Taenia Coli in Vitro

The series elastic components (SEC) of the smooth muscle taenia coli of the guinea‐pig have been investigated. The rate of isotonic shortening after release of an isometrically contracting taenia coli showed that the muscle behaved like a model with contractile elements in series with elastic components. Thus taenia coli has SEC in the same sense as it has been described for striated muscles and heart muscles. At 37°C and full isometric tension the SEC in taenia coli in vitro were measured to be extended on the average 13.1 ± 2.7 per cent of L o . Maximum “isometric” work developed during an isometric contraction was approximately 30 per cent of the maximum work that the muscle could perform during an isotonic shortening.