232 R. G. HOSKIKS 



extent upon the nerve cells is indicated by results previously reported by 

 Beifeld, Whaslon, and Lovelette. These investigators found that the vaso- 

 motor reaction to nicotin in dogs was strikingly augmented following the 

 intravenous administration of saline extracts of the pancreas or the sali- 

 vary glands. That this was not a foreign protein reaction was shown by 

 the fact that the augmentation could be obtained when the animal's own 

 glands were used. It was shown by Hoskins and Ranson that nicotin 

 stimulates the vasomotor system partly at the sympathetic ganglia and 

 partly in the central nervous system. Which of these possible loci was 

 affected by the tissue extracts, Beifeld and his collaborators did not 

 determine. 



Collip(fr) (1920) has investigated also the effect of various tissue ex- 

 tracts upon the depressor reaction to epinephrin. Dogs and rabbits served 

 as experimental animals. These were anesthetized with ether. Extracts 

 were made from thyroid, pancreas, thymus, corpus luteum, hypophysis, 

 testes, and parathyroid glands. Sometimes commercial desiccated material 

 was used, at other times the fresh tissue. An appropriate quantity of 

 epinephrin was first administered to bring about a well-marked fall in 

 arterial pressure. The tissue extract was then administered by vein and 

 the same quantity of epinephrin again injected. In a typical instance 

 in a dog 3 c.c. of 1 :50,000 epinephrin caused a fall of 16 mm. in arterial 

 pressure. After the administration of 10 c.c. of thyroid gland extract a 

 sharp fall of pressure again occurred, but the normal level was soon 

 regained. The same quantity of epinephrin was again injected and, 

 instead of a fall of pressure as before, a rise of 20 mm. occurred. Within 

 a short time the effect of the tissue extract was lost and the depressor 

 reaction to epinephrin again reappeared. 



The relation of anesthetics to the reactions to epinephrin has, of course, 

 been incidentally studied many times in connection with observations upon 

 the pharmacology of the drug. That profound anesthesia changes the 

 depressor to a pressor reaction has been reported by Collip, as discussed 

 in another paragraph. If sufficiently .deep the anesthesia decreases the 

 pressor response, as reported by Rous and Wilson (1919). When the 

 pressor response of a dog the blood-pressure of which was determined under 

 cocaiii anesthesia was compared with the reaction of the same animal 

 under moderate ether anesthesia it was found to be decreased (Berry). 

 Subsequently, however, it was found that the cocain used as local anes- 

 thetic had augmented vasomotor irritability. When quinin and urea 

 liydrochlorid was employed and cocain a sensitization" thereby avoided, no 

 significant difference was noted whether the dog was etherized or not. 



That change of temperature may cause reversal of the epinephrin 

 reaction has been shown by Hartman. Having determined that a given 

 dose of epinephrin either had no effect or else caused constriction in a 

 limb, the structure was warmed by heat from an electric lamp. After it 



