Distribution of Choline Esterases in Nerve Tissue as Revealed by Histochemical Methods.

摘要

A histochemical technic which purports to show the sites of activity of certain choline esterases has recently been devised by Gomori ('49). Sites of enzyme activity are revealed by incubated appropriately fixed tissue sections in a substrate containing the choline esters of certain higher fatty acids and in the presence of cobalt salt. Exploratory studies have been made on nerve tissue of the cat and dog using lauroyl, myristoyl, stearoyl, and palmitoyl choline chlorides. The following nerve tissues were examined: spinal cord, medulla, cerebellum, cerebrum, sympathetic and dorsal root ganglia, and peripheral nerve. Evidence for the existence of numerous and specific choline esterases is suggested through the circumstance that nerve tissue of the cat failed to hydrolyze any of the choline esters used. On the other hand, dog tissue yielded a marked hydrolysis with both myristoyl and palmitoyl choline chloride but a negative response for the remaining two substrates. The distribution of choline esterases in the dog can be defined primarily as associated with the supporting tissue elements of nerve tissue. Thus, a selective response was obtained for glial tissue surrounding the motor nerve cells within the ventral horn of the spinal cord, and, in motor nuclei of the brain stem and cerebellum. Further, an intense reaction was obtained for satellite and supporting cells around the nerve cells in the sympathetic and dorsal root ganglia. There is a limited and variable enzyme-response in the cytoplasm of the nerve cell.