Regeneration of the amputated amphibian limb: retardation by hemicholinium-3

Doses of hemicholinium-3 which partially paralyze the larval salamander profoundly retarded regeneration of the amputated hind limb. The drug also reduced the vascularity and mitotic index of the regenerating tissue. After withdrawal of the drug the rate of regeneration returned to normal. Atropine, in a daily dose of 40 milligrams per kilogram of body weight, did not retard growth. These findings suggest that in the salamander acetylcholine may mediate neurotrophic activity.