ADRENALS 643 



which does not seem easily reconciled with the result of Hoskins, 

 that after ligation of the adrenals the excitability of the vaso-motors 

 remains absolutely undiminished. 



So far as our present data go, the function of the adrenal bodies 

 at least that part of their function which is concerned with the 

 liberation of adrenalin is not to be considered a continuous, but 

 an emergency function (Cannon), exerted at times of physical or 

 emotional stress. It has been pointed out, and with much 

 plausibility, that a rapid discharge of such large quantities of 

 adrenalin as could really produce distinct physiological effects 

 would be advantageous in such emergencies. The increased 

 mobilization of sugar, for example, the increased action of the 

 heart muscle, and the shortened clotting time of the blood 

 occasioned by the outpouring of adrenalin in response to the 

 accompanying excitement of fear or rage or pain might be helpful 

 in a struggle associated with trauma. And as evolution has 

 been so closely connected with physical struggle, an adaptive 

 mechanism of this sort may have been developed. 



Chemistry and Formation of Adrenalin. It has been shown (Stolz, 

 Dakin) that adrenalin (C 9 H 13 NO 3 ) is a dioxyphenyl-ethanol-methylamin, 



CH 

 OH.C/\C.CH (OH).CH 2 NH .CH 3 



OH.C CH 



YH 



It has been prepared synthetically, and in the body appears to be 

 formed, probably by the introduction of a methyl (CH 3 ) group, from 

 a compound arising from an aromatic amino-acid, (tyrosin or phenyl- 

 alanin). While the natural adrenalin rotates the plane of polarization 

 to the left, the artificial substance is optically inactive. This is because 

 it consists of equal parts of laevo-rotatory and dextro-rotatory adrenalin. 

 The artificial adrenalin has approximately half the effect of the natural 

 on the blood-pressure, from which it may be inferred that the dextro- 

 rotatory isomer has only a very slight pressor effect. The left and right 

 rotatory moieties have been separated. The former has exactly the 

 same power of raising the blood-pressure as the natural adrenalin, the 

 latter only j^ to ^ as much. Practically the same proportion holds 

 when the power of the two isomers in producing glycosuria is compared. 

 This constitutes important corroboration of the view already referred 

 to (p. 542), that adrenalin glycosuria is caused by an action on the 

 sympathetic system, for the effect on the blood - pressure is known 

 to* be thus produced (Cushny). 



fit is in the medulla of the adrenals that the epinephrin is formed J 

 Trie medullary cells contain a substance which gives a yellow or brown 

 stain with chromic acid or chromates, and for this reason the cells are 

 called chromafnn or chromaphil. Similar cells are found elsewhere in 

 the body e.g., within the sympathetic ganglia, and also strung out 

 in clumps along the course of the abdominal aorta below the level of 

 the adrenal glands (Vincent). These outlying masses of chromafnn 

 tissue appear to contain epinephrin, or a substance with similar physi- 



