THE SUPRARENAL SYSTEM 177 



The discovery that the intravenous injection of the watery 

 extract of suprarenal is followed by specific and well-defined 

 physiological results, started a new era in suprarenal investiga- 

 tion. This discovery was announced by Oliver and Schafer before 

 the Physiological Society of London on May 10, 1894. A year 

 later, Cybulski and Szymonowicz published their results which, 

 though obtained independently, coincided in the main points with 

 those of Oliver and Schafer. An enormous number of experi- 

 ments followed, which not only explored the physiological and 

 pharmacodynamic activity of suprarenal extract down to the 

 minutest detail, but utilized the facts so won to reconstruct in its 

 entirety the chemistry of the suprarenals. 



CHEMISTRY OF THE SPECIFIC ACTIVE SUBSTANCE 

 PRESENT IN THE SUPRARENALS. 



As early as 1856, Vulpian made the discovery that the supra- 

 renal contains a substance which is distinguished by its remark- 

 able colour reactions. It colours green with ferric chloride, and 

 takes on a pink to carmine-red colour when exposed to the air 

 and treated with alkalies or with oxydizing agents, such as 

 iodine-water and chlorine-water. Virchow, who confirms Vul- 

 pian's discovery, found that the characteristic colour reaction is 

 associated with the medullary substance and that it is demonstrable 

 in microscopic sections. According to Virchow, the chromogenic 

 colouring substance is identical with the substance which colours 

 green with ferric chloride, and is not associated with the morphotic 

 elements, but with the secretion, the intercellular substance. In 

 1885, Kruckenberg drew attention to the important fact that this 

 suprarenal chromogen possesses certain properties in common 

 with pyrocatechin, and Brunner (1892) believed that the two 

 substances were identical. 



Oliver and Schafer ascribed the peculiar hasmodynamic action 

 of suprarenal extract to the medullary substance and, following 

 them, Moore found that the substance which produces increased 

 blood-pressure is identical with chromogen, but that its pharmaco- 

 logical properties are entirely different from those of pyrocatechin. 

 S. Frankel (1896) was the first to suggest that the substance which 

 raises blood-pressure is a derivative, containing oxygen, of the 

 pyrocatechin group. The experiments of v. Fiirth and Abel were 

 of great importance because they prepared the way for the 

 isolation, in a state of chemical purity, of the active principle of 

 the suprarenal. In 1901 Jokischi Takamine succeeded in obtain- 

 ing this substance in a crystalline form, and he gave it the name 

 of adrenalin. Almost at the same time and quite independently, 

 Aldrich produced the same substance from the suprarenal, also 

 in the form of well defined crystals. 



The methods of isolating adrenalin are based upon the fact 

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