174 W. B. CANNON 



He also confirmed Ostrogorsky's observation of an augmented flow after 

 sciatic stimulation. This reflex secretion did not occur, however, if 

 both suprarenal glands were extirpated, or if one was extirpated and the 

 vein of the other obstructed, or if both splanchnic nerves were cut. He 

 concluded, therefore, that the anomalous secretion from the denervated 

 submaxillary gland is due to suprarenal secretion resulting from reflex 

 stimulation. 



Cannon (rf) (e) (1917, 1919) making use of some incidental observa- 

 tions of previous investigators, suggested the use of the completely dener- 

 vated heart to demonstrate an increase of epinephrin in the circulating 

 blood. In a cat under urethane, with vagi cut and stellate ganglia excised, 

 stimulation of the central end of the cut sciatic caused the heart rate to in- 

 crease in some instances as much as fifty beats a minute. Reflex in- 

 crease of the cardiac rate did not occur or was slight after the suprarenal 

 glands were removed. 



The foregoing evidence, involving tests made on blood removed from 

 the body, and tests made in the body on the denervated limb, the de- 

 nervated kidney, the denervated salivary gland and the denervated heart, 

 are harmonious in testifying to a reflex discharge of the suprarenal 

 glands when a sensory nerve is stimulated. 



Evidence That Suprarenal Secretion is Induced by Asphyxia. In 

 their examination of the effect of asphyxia on suprarenal secretion, Can- 

 non and Hoskins, in 1911, used the same methods that were employed 

 for testing the effect of sensory stimulation. In the course of the exam- 

 ination it was discovered that extreme asphyxia would cause a change in 

 the blood which would produce the same effect as epinephrin on the beat- 

 ing intestinal strip, i. e., inhibition, and this even though the suprarenal 

 glands had been carefully removed or the circulation confined to the 

 region above the diaphragm. This observation indicated the necessity 

 for careful control at the time the asphyxial blood was taken. Accord- 

 ingly, after moderate asphyxia, there was removed, from the femoral vein, 

 blood which should serve as a control sample of the systemic venous flow 

 below the entrance of the lumbo-suprarenal veins; and at as nearly as 

 possible the same time another sample was removed from the inferior 

 vena cava at a point anterior to the opening of these veins. This latter 

 blood caused the typical inhibition indicating the presence of suprarenal 

 secretion, whereas the control femoral blood, like the vena cava blood 

 taken before asphyxia, failed to cause inhibition. Through the use of the 

 control, therefore, the presence of an accessory factor, simulating the 

 action of epinephrin, was ruled out. Consequently the conclusion was 

 drawn that asphyxia results in secretion of the suprarenal glands. 



In 1912, Anrep(a) noted that a decrease in volume of the denervated 

 limb and denervated kidney occurred during asphyxia, in spite of a general 

 rise of arterial pressure, just as he had seen it occurring as a consequence 



