THE SUPRARENAL SYSTEM 249 



Although these figures possess an approximate value only, 

 they show that the adrenalin contents in proportion to body weight 

 are very much the same in different animals. The guinea-pig 

 forms the only exception, the adrenalin contents in this instance 

 being twice, or nearly three times, as large as in other animals. 



Quantitative chemical tests for adrenalin have not as yet been 

 carried out by means of the more improved modern methods. The 

 following facts have been ascertained concerning the adrenalin 

 contents of the suprarenals under both physiological and patho- 

 logical conditions. 



Langlois and Rehns found that the suprarenals of foetuses 

 yielded, at the end of the first half of pregnancy, extracts which 

 produced a rise in blood-pressure, and also gave a positive reaction 

 with ferric chloride. Judging by the chromium reaction, the 

 portions of the adrenal system which are external of the supra- 

 renals contain adrenalin earlier in the life of the embryo than the 

 cells of the medulla (Wiesel). 



That the adrenalin contents of the suprarenals are affected 

 by changes in the physiological conditions, was first shown by 

 Battelli and Roatta. These authors found that the amount of 

 adrenalin in the suprarenals of dogs, which had been allowed to 

 run in a treadmill until completely exhausted, was reduced to a 

 third of the minimal normal amount. Where the muscular 

 exertion was followed by muscular repose of several hours dura- 

 tion, the adrenalin contents became increased until far in excess 

 of the normal. 



Schur and Wiesel confirmed these results also with dogs. 

 They found that, after running at the treadmill for six to seven 

 hours, there was a distinct reduction in the cells of the medulla 

 and total disappearance of their chromaffinity ; there was no 

 reaction to ferric chloride; and extract of these suprarenals failed 

 to produce mydriasis. By means of the last-named test, they 

 proved that, at the same time, the blood contained a large amount 

 of adrenalin. Schur and Wiesel also discovered that prolonged 

 anaesthesia, as the result of ether, chloroform, or A.C.E. mixture, 

 produced in rabbits a reduction, or even complete disappearance, 

 of the adrenalin in the medulla as well as of the chromaffinity of 

 the latter, while at the same time adrenalin was found to be 

 present in the blood. Kahn, however, was unable to confirm the 

 results of Schur and Wiesel, either after muscular fatigue or after 

 prolonged narcosis. 



Considerable interest is attaching to the manner in which the 

 adrenalin contents of the suprarenals are modified by pathological 

 conditions. It has long been known that, in certain infective 

 diseases, changes take place in the suprarenals, and these have 

 been studied by means of experiment. Roux and Yersin 

 described a high degree of hypera?mia in the suprarenals of 

 guinea-pigs, after experimental diphtheritic infection or poisoning 



