Acetylcholine and adrenaline-noradrenaline sensitivity in denervated parotid gland of monkey.

The mechanism underlying a phenomenon of such a general occurrence as the supersensitivity after denervation has often been attributed to a decrease of the enzyme cholinesterase in the tissues concerned. Different organs exhibit varying degrees of hypersensitivity; skeletal and smooth muscle, glands, autonomic ganglion cells and neurones of the spinal cord and brain all develop this post-denervation sensitisation. Cannon (1939) in his 'Law of Denervation' states "When the efferent neurones in a unit are sectioned, an increased iritability to chemical agents develops in the denervated segment".