Myofibers sarcolemma mechanical properties are affected by the isolation method

Abstract

For understanding the mechanics and function of skeletal muscle in vivo, isolated cell fibers are used. Single isolated myofibers can be obtained from direct dissection or enzymatic dissociation. Isolation via direct dissection allows control of sarcomere length, preserves tendon attachment and, maintains the physiological environment, but is labor‐intensive and time‐consuming. On the contrary, enzymatic dissociation is fast and facile, produces hundreds of myofibers, reduces the number of muscles/animals needed for studies but alters the physiological environment and sarcomere length cannot be controlled. Biomechanical properties of the sarcolemma from mice were studied using the Elastimetry technique applied on myofibers from the extensor digitorum longus dissected directly and from the flexor digitorum brevis obtained by dissociation. Membrane stiffness, Young’s modulus, strain, and viscoelasticity in single isolated fibers were measured. Results showed that the membrane biomechanical properties were up to two times higher using direct isolation compared to the enzymatic dissociation technique. This leads us to conclude that the method used to obtain the myofibers changes the mechanical properties in cells.