THE DUCTLESS GLANDS 1237 



Owing to the rapid destruction of adrenaline, relatively enormous doses have to be 

 given by the mouth in order to produce any effect on the blood pressure. There is 

 however a whole series of substances, more or less allied to adrenaline in chemical con- 

 stitution, which undergo less rapid destruction and can therefore be administered 

 as drugs in the usual way. Dale and Barger have recently described three such sub- 

 stances as occurring in infusions of putrid meat and as forming the most important of 

 the active principles of ergot. The constitution of these substances is shown in the 

 following formulae : 



CH 3 



^CHCH 2 CH 2 NH 2 Isoamylamine 



\ 



HO/ > CH 2 CH 2 NH 2 p-hydroxyphenylethylamine 







> CH 2 CH 2 NH 2 phenylethylamine 



HO 

 / N > CH(OH)CH 2 NHCH 3 adrenaline 



The formula of adrenaline is placed below in order to show the relation of these 

 substances to the natural hormone. These bodies are produced from the amino-acids 

 of proteins by a process of decarboxylation. Leucine would yield isoamylamine, 

 tyrosine, hydroxyphenylethylamine, and phenylalanine would give phenylethylamine. 

 Such substances may be formed in minute quantities during the normal processes of 

 putrefaction which occur in the alimentary canal. 



There seems little doubt that we must regard adrenaline as a true internal 

 secretion, and therefore must ascribe to the medulla of the suprarenal capsules 

 as well as to the other chromaffine tissue in the body, the function of main- 

 taining the normal constriction of the arterioles and of facilitating in some 

 way or other the functions of the sympathetic system generally. The 

 absence of this secretion in cases of destruction by disease of the suprarenals 

 would serve to account for the weakness, prostration, and lowered blood 

 pressure of Addison's disease. The two other symptoms of this disease, 

 namely, bronzing and vomiting, still remain to be accounted for. It is 

 possible that the latter may be due to some involvement by the morbid 

 process of the numerous fibres of the solar plexus, which run in close 

 proximity to the suprarenals. We have no knowledge whatsoever of the 

 functions of the cortical portion of these organs* It is possible that future 

 work may show some connection between the cortex and the destruction of 

 pigment in the body. At present it is only by a process of exclusion that 

 we may guess at a causal relationship between the destruction of the cortex 

 and the bronzing which occurs in Addison's disease. 



There seems little doubt that the rapidly fatal effects of extirpation of 

 both suprarenals is to be ascribed rather to the removal of the cortex than of 

 the medulla. The functions of the latter can be more or less effectively 

 maintained by the other chromafnne tissues found at the back of the 

 abdomen. In the few cases, where animals have survived double extirpation, 

 small masses of accessory cortical substance have been found embedded in 



