Cholinergic growth factor from skeletal muscle elevated following denervation.

The effect of skeletal muscle extracts upon cholinergic neuron in vitro survival was investigated. All muscle soluble protein extracts elicited survival of neurons above that of neurons alone in culture and were found to be active below a protein concentration of 1.0 mg/ml. However, skeletal muscle which had been previously denervated, was found to contain higher amounts of survival activity than innervated muscle extracts. This elevation of survival activity was greatest within the first 7 days post-denervation, but subsequently declined towards the innervated level.