78 



Scientific Proceedings (80). 



ment (trauma, anesthesia, etc.)- For, by electrical stimulation 

 of the cut splanchnic, the rate of liberation can be made decidedly 

 greater than the rate of spontaneous liberation with intact splanch- 

 nics. 



2. Unlike the rate of liberation per unit of time, the concentra- 

 tion of epinephrin in the adrenal vein blood can be observed to 

 vary decidedly in the course of an experiment, increasing, in 

 general, as the rate of blood flow decreases. This can be shown 

 by collecting adrenal vein blood in successive samples. When the 

 blood flow slackens, owing to hemorrhage or other circumstances, 

 the earlier specimens will be found to contain a smaller concen- 

 tration of epinephrin than the later specimens. 



For example, in a dog, weighing 10 kg., the first sample from the cava pocket, 

 into which the adrenal veins were alone discharging, flowed at the rate of 8 c.c. per 

 minute, the second sample 7.2 c.c, third 5.8 c.c, fourth 4.4 c.c, fifth 3.2 c.c, sixth 

 2.4 c.c, seventh 1.5 c.c. A definite increase in the epinephrin concentration in the 

 successive samples was clearly shown by the intestine and especially by the uterus 

 tests. The concentration was assayed in the first sample at somewhat more than 

 1 : 3,300,000; in the third sample at somewhat more than 1 : 1,670,000; in the 

 seventh sample at somewhat less than 1 : 750,000. 



The increase in the concentration in the blood is far too great 

 to be accounted for by any increase in the relative proportion of 

 plasma to corpuscles associated with hemorrhage without change 

 in the concentration of epinephrin in the plasma. And it has 

 been demonstrated that the sera separated from the successive 

 samples of blood show a progressively increasing concentration of 

 epinephrin. 



Even when the circulation through the adrenals is stopped 

 altogether by clamping the veins, the liberation of epinephrin into 

 the pent-up blood continues for a time at an apparently undi- 

 minished rate and the concentration of epinephrin in the blood 

 must go on increasing. 



3. For the reason mentioned in paragraph 2 it is not in general 

 permissible to deduce changes in the rate of liberation of epine- 

 phrin from changes in its concentration in the adrenal vein blood, 

 unless the rate of blood flow through the adrenals is known. 

 Changes in the concentration of epinephrin in the blood of the 

 inferior cava above the adrenals can be produced by alterations 

 in the rate of blood flow in the cava, even where the rate of liber- 

 ation of epinephrin from the adrenals has remained constant. 



