206 



K. G. HOSKINS 



Fig. 5. Graph showing contraction of the 

 normal leg of a dog as result of infusion of a 

 depressor dose of epinephrin by vein. (Reduced 

 to one-half.) (After Hoskins, Gunning, and 

 Berry, Am. J. Physiol. ) 



The foregoing observations had been interpreted as indicating that 

 epinephrin causes vasoconstriction in skeletal muscle, but the effect of the 

 drug on the cutaneous vessels in such experiments had not received ade- 

 quate consideration. That it 

 causes vasoconstriction in the 

 skin had been reported by Ve- 

 lich, Baum, Elliott, and Vin- 

 cent. From the study of the 

 limb as a whole, therefore, 

 without taking into account 

 the extent to which the skin 

 participates in the reaction, no 

 conclusion is justified regard- 

 ing the effects in the muscle. 

 The differential effects in 

 both skin and muscle were 

 studied by Hoskins, Gunning, 

 and Berry (1916). Dogs were 

 used as the experimental ani- 

 mals. These were anesthetized 

 by ether or ether and morphin. 



The plethysmograph used for the leg was of the familiar Mosso type, con- 

 sisting simply of a glass cylinder of appropriate diameter, adapted to the 

 leg by means of a thin rubber cuff. Injections or infusions of epinephrin 

 were made into a femoral vein. Arterial 

 blood-pressure was recorded simultaneously 

 with the changes of limb volume. 



The effects of epinephrin on the volume 

 of the intact limb were first investigated. 

 Varying dosages were used, from those which 

 gave a fall of systemic pressure to those caus- 

 ing a sharp rise. In most cases the volume 

 of the limb was decreased, irrespective of the 

 systemic reaction. (Fig. 5.) In a few in- 

 stances, however, increased volume was noted. 

 One such case is shown in Fig. 6. The ex- 

 pansion noted by previous observers in such 

 cases had been regarded as merely passive. 

 In this case it is to be noted that the limb did 

 not begin to increase in volume until the 

 general pressor reaction had passed and it 



continued for some time after the pressure had regained essentially its 

 normal level. The expansion was obviously due, therefore, to some other 

 factor than elevation of systemic pressure. In all, 156 experiments were 



Fig. 6. Graph showing ex- 

 pansion of normal leg of dog 

 under the influence of epineph- 

 rin by vein. (Reduced to one- 

 half.) (After Hoskins, Gun- 

 ning, and Berry, Am. J. 

 Physiol. ) 



