Hydrodynamic properties of water in contractile system

When muscle fragments are compressed, intracellular water leaks out. Unexpectedly, y-intercepts of regression lines in resting and active states become negative, implying "negative compression". It seems that in resting state there is a kind of mechanical equilibrium between proteins and water. This protein-water complex in muscle behaves like a synthesized elastomer under moderate extension, (less than 10%). Employing the data presented by Richie & Wilkie (1958), validity of elastomer model is examined. Compression study also shows that in active state a frictional drag of intracellular water decreases markedly. It leads to the assumption that the negative mechanical resistance may play a role in regenerative activation.