Emetic Action of the Digitalis Bodies. 7 



4 (i75i) 



Further observations on the seat of the emetic action of the 



digitalis bodies. 



By ROBERT A. HATCHER and SOMA WEISS. 



[From the Department of Pharmacology, Cornell University Medical 

 College, New York City.} 



The application of digitalis bodies directly to the vomiting 

 center, described by Thumas, does not cause emesis. 



When a digitalis body is injected into a cat in which the spinal 

 cord has been cut at about the level of the second thoracic vertebra, 

 vomiting does not usually occur, but when the cord is severed at 

 the level of the 5th thoracic vertebra vomiting is not prevented. 



Removal of the stellate ganglia frequently prevents this 

 emesis, and removal of the stellate ganglia with cutting of both 

 vagi prevents the emesis in nearly every case. 



Removal of the celiac plexuses does not interfere with the 

 emesis following the injection of digitalis bodies. 



When the nerve supply to the heart is intact the injection of 

 a digitalis body causes emesis, if the animal is in good condition. 

 When all nerve supply to the heart is severed s digitalis does not 

 cause emesis, but mercuric chloride still causes vomiting in the 

 usual way. 



Impulses appear to pass up from the heart to the vomiting 

 center chiefly by the way of the sympathetic, and to a less, though 

 probably variable, extent by way of the vagus. When the 

 sympathetic is cut the administration of ouabain usually fails to 

 induce emesis. This may be due to the fact that the impulses 

 passing up the vagus are usually insufficient to set up the coordi- 

 nated reflex, or it may be that in those cases where vomiting is 

 not elicited by this drug after the sympathetic is cut the vagus 

 does not contain any fibers concerned in this reflex. 



Evidence is presented to show that digitalis bodies induce 

 emesis by reflex action due to irritation of the heart or its ap- 

 pendages. 



This is almost certainly a protective mechanism for the heart 

 such as is recognized in the case of other organs. 



