254 INTERNAL SECRETION 



PHYSIOLOGICAL ADRENALIN.EMIA. 



The secretion from the intracapsular portion of the adrenal 

 system is continuously supplied to the general circulation by way 

 of the suprarenal vein ; thus the blood always contains a certain 

 amount of adrenalin, and a physiological adrenalinsemia is 

 maintained. 



Battelli was the first to prove the presence of adrenalin in the 

 peripheral blood. After suitable concentration, he tested the vaso- 

 constrictor action of normal serum from dogs, and found that its 

 action was equal to that of an adrenalin solution of i :io to i : 20 

 millions. 



Ehrmann was unable to obtain mydriasis of frogs' eyes with 

 serum from the peripheral blood of rabbits. According to Schur 

 and Wiesel, both Ehrmann's reaction and the ferric chloride test 

 are invariably negative. O. B. Meyer, however, proved the 

 presence of adrenalin in normal blood serum by means of portions 

 of blood-vessels from the living body, this test being more 

 sensitive than the above-named reactions. By the same method, 

 Schlayer proved the presence in human blood-serum of a sub- 

 stance which produces vaso-contraction. 



Fraenkel advanced conclusive proof of the presence of 

 .adrenalin in the serum of blood in the peripheral vessels. He 

 found that serum from rabbits and cats, when diluted to twice its 

 volume, was invariably active in the uterus of rabbits after 

 removal from the living body. Human sera from healthy subjects, 

 either undiluted or in solutions of 1:5 and i : 10, produce 

 phenomena similar to those resulting from adrenalin. Similar 

 results have been occasionally obtained with solutions of i :2 and 

 i =40 and, in three instances, with i 150. Judging by the results 

 of Fraenkel's experiments, the minimal adrenalin contents of 

 i c.cm. of peripheral blood may be estimated at .0000001 mg., 

 the maximal adrenalin contents at about .0000025 mg. 



Using these figures as a basis, the total adrenalin contents of 

 a dog weighing 15 kg. is as follows : The whole of the blood 

 provision is 1200 c.cm. and contains a minimum of .00012 mg., 

 .a maximum of .003 mg. adrenalin. Now compare with these 

 figures the amount which passes from the suprarenals into the 

 vena cava. Before this can be done, however, we must know^ the 

 velocity of the blood circulating in the suprarenals. There is no 

 direct information as to the volume of the blood in the suprarenal 

 veins. In certain older experiments of mine, I estimated the 

 amount of venous outflow by counting the drops as they left the 

 veins, and I reckoned that, in a dog weighing 15 kilo, the maximal 

 velocity of the stream was roughly .1 c.cm per second. These 

 figures are the same, though this is by the way, as those more 

 exact results which Burton-Opitz obtained with Hurthle's velocity 

 register (Stromuhr) in the case of the blood flowing through the 



