alsberg: biochemical analysis of nutrition 277 



The iodine compound of the thyroid gland is physiologically 

 active; that is to say, it is poisonous. It is not, however, the 

 only physiologically active substance produced from amino- 

 acids in the animal metabolism. ^Adrenaline 



C H 

 (HO)C^ '\>CH(OH)CH 2 -NHCHr, 



(HO)C< ^C 



V 



is another such substance probably derived from an amino-acid. 

 As you may see by comparing the formulae, it is related to the 

 amino-acid tyrosine. It is formed in the adrenal glands, two small 

 glands found in the kidney fat just above the kidneys. Hence 

 their name, which was given to them before it was known that 

 they have no direct relation to the kidneys. They apparently 

 furnish adrenaline to the blood. Adrenaline when injected into 

 the blood causes the small blood vessels to contract and therefore 

 the blood pressure to rise, since the heart then pumps against 

 the increased resistance of the contracted vessels. When the 

 adrenal glands do not function normally, as for example when 

 they are tuberculous, Addison's disease develops, which is 

 characterized among other symptoms by a low blood pressure. 

 The substance adrenaline is probably known to you, since it is 

 used therapeutically in a number of ways, for instance, to con- 

 strict capillary blood vessels to stop bleeding from the capillaries 

 on wound surfaces. If there is an absence from the diet of the 

 material necessary to form adrenaline, it is conceivable that 

 symptoms other than those of starvation might result. 



There is a small gland at the base of the brain known as the 

 pituitary gland, which is apparently necessary to life and which 

 manufactures a physiologically active substance, probably de- 

 rived from the amino-acid histidine. Disease of this gland 

 seems to occur in certain giants and in the disease akromegaly, 

 in which among other symptoms is . found enlargement of the 

 bones of the face and the extremities. 



A very interesting physiologically active substance, para- 



