Action of the Shigella shigae Toxin after Intracerebral Injection

Abstract

USING the technique of Feldberg and Sherwood¹, we injected small amounts of Shigella shigae toxin, prepared in a way previously described², into the left ventricle of unanæsthetized cats. Doses of 1–10 µgm. were used. For 3–4 hr. the behaviour of the animals did not change. Then gradually the cats became unusually quiet and sat still in their cage, although before they were very enterprising. Although a normal cat always tries to get out of the cage, these animals stayed in it in spite of the open door and when taken out and put on the floor of the room they invariably returned to the cage. They walked as if the co-ordination of the fore- and hind-legs was impaired. Their respiration was very rapid, the head showed a slight tremor, and they avoided light. This state continued for several hours. The animals kept their orientation, however. Even a 1-µgm. dose may kill a cat within 24 hr., a state of stupor with marked hypotonia preceding death.