Expression of nestin, desmin and vimentin in intact and regenerating muscle spindles of rat hind limb skeletal muscles

Abstract

We describe the expression and distribution patterns of nestin, desmin and vimentin in intact and regenerating muscle spindles of the rat hind limb skeletal muscles. Nestin expression in intact spindles in host muscles was restricted to Schwann cells of sensory and motor nerves.

In transplanted muscles, however, nestin expression was also found in regenerating spindle fibers, 7 and 16 days after grafting. Desmin was detected in spindle fibers at all developmental stages in regenerating as well as in intact spindles.

Vimentin was expressed in cells of the outer and inner capsules of all muscle spindles and in newly formed myoblasts and myotubes of regenerating spindles 7 days after grafting. Our results show that the expression pattern of these intermediate filaments in regenerating spindle fibers corresponds to that found in regenerating extrafusal fibers, which supports our earlier suggestion that they resemble small diameter extrafusal fibers.