194 BIOLOGICAL CHEMISTRY 



Takamine isolated the active substance,* and as the result 

 of the work of Abel and others the chemical formula was 

 identified and the substance was synthetised by Friedmann.t 

 CHOH-CHo(NHCH 3 ) 



- 



x^ 



This formula contains an asymmetric carbon atom, thus there 

 are two optical isomers, and the physiological activity is due 

 to the laevo form. 



There are two types of structure in the adrenal glands, 

 named cortex and medulla respectively. The substance that 

 produces a rise in blood pressure is obtained from the medulla. 



The medulla of the adrenal glands stains brown when placed 

 in solutions of potassium bichromate. Other tissues which 

 stain brown with bichromate give extracts which cause a 

 rise of blood pressure. We speak of such tissues as chromaffine, 

 and the extracts as pressor. Such substances are found 

 throughout the vertebrate kingdom J and also in inverte- 

 brates^ 



The cortex of the adrenal glands contains a large amount 

 of lipoid tissue, and it is probably related to the sexual glands. 

 It is of interest that the cortex is derived from the germinal 

 epithelium and is related to the sexual glands, whilst the 

 medulla is derived from the sympathetic nervous system 

 and its extract acts on the terminations of the sympathetic 

 nerve fibres. 



CHEMICAL CONSTITUTION AND PHYSIOLOGICAL ACTION 



The active substance obtained from the adrenal gland 

 (adrenaline) is interesting from the pharmacological point of 

 view. The action of drugs depends upon their physical and 

 chemical properties. The physical properties predominate 

 in those substances which possess a general action, whilst the 

 chemical characteristics are associated with specific or 

 localised activity. A detailed examination of active substances 

 shows that their activity depends upon the presence of special 

 groups and their relation to each other in the molecule. In 



* J. Takamine, Journ. Physiol., 1901, vol. 27, proc., p. xxix. 



f E. Friedmann, Beitrage z. chem. Physiol. it. Path., 1904, vol. 6, p. 92. 



J S. Vincent, Internal. Monatschrift f. Anat. u. Physiol., 1898, 

 vol. 15, p. i. 



M. Nierenstein and H. E. Roaf, Journ. Physiol., 1907, vol. 36, 

 proc., p. v., and J. F. Gaskell, Phil. Trans., 1914, B. vol. 205, p. 153. 



