Abstract
After a single injection of calcitonin (20 M.R.C. [mouse radius calcifying] units/kg body wt.) marked decreased plasma Ca2+ and free tryptophan were observed during the initial treatment period (up to 1 h). 5-Hydrotryptamine contents of the whole brain and cerebral acetylcholinesterase activity were greatly enhanced. Cerebellar acetylcholinesterase activity was not influenced by calcitonin.