THE ADRENAL BODIES 195 



Dakin. The reduction product appears to be chemically iden- 

 tical with adrenalin in all respects except that it is optically 

 inactive, while the natural body from the adrenal medulla is 

 laevorotatory ( a D = 43) according to Pauly. 



On testing the physiological action of the synthetic (racemic) 

 adrenalin and comparing it with that of the natural adrenalin, 

 Cushny found that the latter acts twice as strongly on the 

 blood-pressure as the former. From this he inferred that 

 dextro-adrenalin is devoid of any physiological activity. 

 Adrenalin thus proves analogous to hyoscyamine and hyoscine, 

 in which the dextrorotatory form is almost devoid of the 

 specific action of the natural laevorotatory alkaloid on the 

 peripheral tissues. 



Flacher recently succeeded in dividing the racemic suprarenin 

 or adrenalin into its two optically active components. These 

 have been subjected to a pharmacological examination by 

 Cushny. The synthetic ^-adrenalin was first compared with 

 natural adrenalin isolated from the glands, and was found to 

 be identical with it in its power of raising the blood-pressure. 

 The d-adrenalin was next compared with these and found to 

 possess one-twelfth to one-fifteenth of their action that is, 

 twelve to fifteen times as much of ^-adrenalin was required to 

 raise the blood-pressure to a definite degree. The earlier 

 statement of Cushny that the laevorotatory alkaloid is twice as 

 strong as the racemic is thus seen to be practically correct, 

 these later experiments showing that a closer approximation 

 would put the relative strengths between 24 : 13 and 30 : 16. 

 Cushny found further that the doses necessary to cause 

 glycosuria are similarly in the proportion of 12 to 18 : 1. The 

 minimal lethal doses as tested by subcutaneous injection appear 

 to bear the same relation. No evidence was obtained suggest- 

 ing that adrenalin acts elsewhere than on the receptive 

 substances of the sympathetic myoneural junction. 



We have seen that the terms " epinephrin," ".sphygmo- 

 genin," " suprarenin," and " adrenalin " have been applied to 

 the active principle of the chromaphil tissues. Other names 

 which have been employed are " hemisin," " paraganglin," 

 and " myosthenin." Adrenalin is, however, the term most 

 commonly used ; but it is advisable to adopt a name which 

 has no commercial attachments, and Schafer suggests 

 " adrenin." This term has been adopted in the present work, 



