Plastic properties of vertebrate smooth muscle (taenia coli of the guinea pig).

After extension and creep due to a constant load the taenia coli of the guinea pig shows plastic deformation. The deformation is partially abolished by complete unloading: to 51% in the relaxed and to 83% in the depolarized = contracted state. The quantitative relations between creep (N) and its time derivative (dN/dt) as well as those between stress relaxation (R) and dR/dt stated in our previous papers, remain valid if plastic deformations have occurred during these processes.