Abstract
Veratramine, a secondary amine of veratrum alkaloids, was isolated first by Saito (1) from the Japanese Veratrum grandiflorum and found later by Jacobs and Craig (2) in the American Veratrum viride. Its pharmacological actions were studied first by Krayer (3) and later by many investigators. The most important property of this alkaloid is considered to be the antiaccelerator action on the heart, which was discovered by Krayer and has been thoroughly studied by him and his coworkers (4-10).
Another remarkable action of veratramine is the excitatory action on the central nervous system. This was found also by Krayer at the same time the antiaccelerator was discovered, but relatively little attention has been focused on this subject ever since. Krayer, the first reporter, described briefly that clonic convulsion occurred in dogs and it was suppressed by pentobarbital. Few other investigators observed also convulsive action of veratramine while they studied on its cardiovascular action (11-13). However nobody had studied in detail on its central action until Tanaka (14) took up this project. In his study on the central actions of veratrum alkaloids in mice, Tanaka pointed out that veratramine caused a unique excitation which was expressed as “struggling” movement and was antagonized by mephenesin or ether. Despite his relatively comprehensive survey on this project, the site of action of veratramine remained unelucidated.
The present investigation was designed to supplement the study of Tanaka on the central action of veratramine, by determining if the same excitation could be observed in other species of experimental animal, by searching for the antagonists against the excitation, by observing the influence of elimination of some parts of brain, by recording the electroencephalogram and by studying the circulatory effect when administered directly to the central nervous system.
