Neuronotrophic effects of skeletal muscle fractions on neurite development.

Soluble fractions of chick embryonic skeletal muscle stimulated radial outgrowth of long neurites from peripheral ganglia. Dorsal root ganglia were more responsive to the growth stimulus of muscle fractions than sympathetic ganglia. Muscle fractions from chicks immobilized with d-tubocurarine chloride (dtc) were significantly more effective in stimulating growth than normal muscle fractions. Neuritic outgrowth stimulated by muscle fractions was not blocked by antisera to the Nerve Growth Factor (NGF) indicating that these neuronotrophic effects were not due to NGF.