THE SUPRARENAL SYSTEM 275 



Nabarro's experiments have acquainted us with the albu- 

 minoids of the suprarenal. These experiments show that the 

 suprarenal contains an albumin which coagulates at 70, certain 

 globulines which coagulate at between 56 and 75 ; and one or 

 more nucleoproteids. Thus far, then, the suprarenals do not 

 differ from the other organs, seeing that the globulins and the 

 nucleoproteids are present in all tissues. According to the older 

 accounts, the suprarenal contains also the following : of the pro- 

 ducts of regressive metamorphosis it contains hippuric and tauro- 

 cholic acid (Vulpian and Cloez), benzoic acid and taurin (accord- 

 ing to Seligsohn, but not confirmed by Stadelmann), leucin, 

 tyrosin, xanthin bases (xanthin, methylxanthin, hypoxanthin, 

 epiguanin, according to Okerbloom), inosit (Kiilz) ; of the carbo- 

 hydrates it contains glycogen (Lubarsch), a substance resembling 

 jekorin (Manasse), and salts, of which potassium phosphate is 

 present in exceptionally large quantities (Halliburton). 



A. C. Croftan discovered a diastatic ferment, and M. Jacoby 

 an oxidative ferment, an aldehydase, in the suprarenal cortex. 

 The suprarenal further contains a nuclease which splits up nucleo- 

 proteids, xanthin bases being formed (Jones). 



The proof of the presence of cholin in the suprarenal was a 

 discovery of the highest importance. As early as 1888, it was 

 stated by Guarnieri and F. Marino-Zucco that w^atery extracts of 

 suprarenal contain neurin (in the terminology of to-day, cholin) 

 and they assumed that the neutralization of the neurin in the 

 body was a function of the suprarenals. Exact proof of the pre- 

 sence of cholin was, however, first offered by Lohmann (1907). 



It w T as Lohmann T s object to isolate from the suprarenal the 

 substance present in suprarenal extract which produces an effect 

 first observed by Giirber, namely, the lowering of blood-pressure. 

 The suprarenal was first freed from fat and cut into small pieces, 

 and, by means of hot water with the addition of a small amount 

 of acetic acid, a triple extract was obtained. The concentrated 

 extract was purified by Kutscher and Steudel's method with 

 tannin, baryta and oxide of lead, and afterwards precipitated with 

 phosphorotungstic acid. The precipitate was split up with baryta 

 and the alloxur, or purin, bases were first extracted by means of 

 nitric acid, and a further group of bases, " the arginin fraction," 

 was afterwards extracted with baryta. The filtrate was again 

 precipitated with phosphorotungstic acid, the precipitate again 

 split up with baryta, and, after removal of the superfluous baryta 

 with carbonic acid, the bases were reduced to a thick syrup. A 

 concentrated extract of this syrup was obtained by repeated treat- 

 ment with boiling absolute alcohol. The bases obtained from 

 the alcohol extract possessed marked hypotensive properties. The 

 concentrated alcoholic extract was precipitated with alcoholic 

 solution of platinic chloride. The platinates, which were in- 

 soluble in alcohol, w r ere converted into chlorides with sulphuretted 

 hydrogen, and then, by the addition of a watery solution of auric 



