THE ADRENALS AND ADDISON'S DISEASE 499 



entirely, to the presence in the gland of a specific substance with 

 remarkably great power of raising blood pressure by causing 

 general arterial contraction, at the same time causing contraction 

 of all other voluntary muscles that are under control of the 

 sympathetic nervous system. 1 According to Langley 2 and to 

 Elliot, 3 adrenal extract acts upon some receptive substance pres- 

 ent in the muscle, which is independent of the nervous system, 

 since the muscles react to adrenalin after the nerves have been 

 sectioned and even after their fibrils and endings have degenerated. 

 Adrenal administration seems to have no marked or constant 

 effect upon metabolism, for most of the results reported in the 

 literature are very contradictory, some observing nitrogen loss 

 and some nitrogen retention. 4 



The active substance has been isolated in pure crystalline form, 

 and although various names have been given to it, adrenalin is 

 the one in most general use. As yet unanimity has not been 

 reached concerning the structural composition of adrenalin, 5 but 

 it is unquestionably related to pyrocatechin, 



-P . : 



and the formula accepted by the majority of chemists 6 is 

 HO / > - CHOH - CH 2 NH - CH 3 . 



This view of its structure suggests that it is derived from the 

 aromatic groups of the proteid molecule. 7 Dakin, 8 starting with 

 pyrocatechin, has synthesized a substance with the same formula 

 as that given, which has physiological effects similar to those of 

 the natural adrenalin, although the synthetic substance differs 

 from the natural in being optically inactive. 



Important as this substance is, its production is probably not 

 the sole function of the gland, for the administration of adren- 



1 Moore and Purinton (Amer. Jour. Physiol., 1900 (4), 51) state that the 

 embryo human adrenal has no effect on blood pressure, and does not give the 

 characteristic " chromogen " reaction with ferric chloride. 



2 Jour, of Physiol., 1905 (33), 374. 



3 Ibid., 1905 (32), 401. 



*Vollbracht, Wien. klin. Woch., 1899 (12), 737; Pickardt, Berl. klin. 

 Woch., 1898 (35), 727; Kaufmann, Cent. f. Stoffwechsel, 1901 (2), 173. 



5 See Abel and Taveau, Jour. Biol. Chem., 1905 (1), 1. 



6 See Friedmann, Hofmeister's Beitr., 1906 (8), 95. 



7 See Halle, Hofmeister's Beitr., 1906 (8), 276; also Friedmann, /oc. cit. 



8 Jour, of Physiol., 1905 (32), p. xxxiv; Proc. Koyal Soc., 1905 (76), 491. 



