Atrioventricular Rhythm in Man. 17 



species only. Kepinow used two kinds of pituitary material, 

 an extract prepared by himself, and the commercial preparation 

 "Pituitrin" made by Parke Davis and Co. Kepinow states that 

 both preparations gave similar effects. Our experiments were 

 made ivith "Pituitrin" only. 



Since the results are negative they may be reported very 

 briefly. The procedure was to determine the effects of injections 

 of given quantities of "adrenalin" and of nicotin, selected to give 

 a moderate rise of blood pressure. About 1 c.c. of adrenalin, 

 1 : 100,000, and 1 c.c. of nicotin 1 : 4,000 are suitable for medium- 

 sized dogs. Having determined the reactions to these drugs, 

 pituitrin was injected by vein in quantity to give a slight rise of 

 pressure, e. g., .05 c.c. At various intervals from one half to 

 several minutes after this injection, the adrenalin and nicotin 

 injections were repeated. In no case was a significant change of 

 reaction noted. In most of the animals the vagi were cut, but 

 this procedure made no apparent difference in results. 



In view of the restricted value of negative results some hesi- 

 tancy is felt in offering them for publication. In further con- 

 sideration, however, of the vast number of unjustified generaliza- 

 tions in the literature of internal secretion they are offered for 

 what they may be worth. 



13 (1077) 



The production of atrioventricular rhythm in man after the 

 administration of atropin. (Preliminary Communication.) 



By Frank N. Wilson, M.D. (by invitation). 



[From the Department of Internal Medicine, University of Michigan.] 



During the past year two patients with cardiac complaints 

 were given repeated injections of 1 mg. atropin sulphate and on 

 each occasion atrioventricular rhythm was observed. This usually 

 appeared in from eight to ten minutes after the drug was given, 

 it persisted for only a few minutes, and disappeared before the 

 maximum effect of the drug was reached. 



In order to determine whether this tendency to A-V rhythm 

 was peculiar to these patients or whether it exists normally, a 



