'234 E. G. HOSKINS 



the dog that the sudden administration by vein of a fairly large dose of 

 sodium carbonate resulted in the change of the depressor reaction to a 

 pressor reaction. A subsequent injection of acid sodium phosphate was 

 found to antagonize the pressor effect. This result proved to be obtain- 

 able repeatedly in the same animal. 



From these data it is evident that the entire pharmacology of epi- 

 nephrin demands re-investigation. The great proportion of the recorded 

 data were obtained before there was any realization of the possibility that 

 relatively slight changes in attendant circumstances may completely reverse 

 the reactions obtainable. 



Conclusion 



In conclusion, it should again be emphasized that most of the data 

 summarized in the foregoing discussion are of pharmacological rather 

 than physiological significance. There is no reliable evidence that epineph- 

 rin is ever discharged from the suprarenal glands in more than minute 

 quantities. Solutions greatly transcending in concentration those found 

 even in the lumbo-adrenal veins have commonly been employed in experi- 

 mentation. 



Hartman envisages the situation as a whole in the following terms: 

 "In the adult, epinephrin poured into the blood in small quantities causes 

 by its peripheral effects constriction of the vessels of the skin, mucous 

 membranes, and abdominal organs, driving the blood into the vessels 

 supplying the skeletal muscles which are actively dilated for its reception 

 through the effect on the sympathetic and dorsal root gangliar mechanisms. 

 But as the quantity of epinephrin increases, the peripheral effect begins to 

 overcome the gangliar effects in skeletal muscle, the intestinal vessels by 

 action on the sympathetic ganglia begin to dilate and the blood is reversed 

 in its path. Although the effect of epinephrin on blood-pressure, a fall 

 with small doses and a rise with larger amounts, is the more evident, the 

 differential effect is the more important." 



