Am.  Jour.  Pharm. 
October,  1920. 
Action  of  Adonis  Vernalis. 
711 
It  has  been  noted  that  digitahs  has  two  distinct  actions  upon  the 
mammaHan  heart.  The  one  is  a  slowing  of  its  rate,  produced  by 
relatively  small  doses  of  digitalis,  and  removed  by  section  of  the 
vagus  nerves  or  by  the  administration  of  atropine.  Adonis  in  a  like 
manner,  in  small  doses,  produces  a  slowing  of  the  heart's  rate,  which 
in  all  cases  can  be  removed  by  atropine.  This  action  may  be  termed 
the  beginning  of  the  action  of  digitalis,  or  of  adonis,  and  is  purely 
a  slowing  of  rate.  Another  phase  of  digitalis  action  is  shown  how- 
ever, in  cases  of  the  administration  of  large  doses  of  digitalis,  espe- 
cially in  cases  of  fatal  poisoning.  This  is  evidenced  by  a  more  rapid 
rate  of  beat,  and  persists  even  after  section  of  the  vagi,  or  the  in- 
jection of  atropine.  Cushny.^^  If  the  adonis  action  were  to  be 
compared  with  digitalis,  it  was  considered  necessary  to  compare  this 
action  also.  Large  doses  of  adonis  given  after  removal  of  vagus 
control,  show  an  increased  rate  of  beat. 
In  order  to  determine  the  action  of  adonis  upon  the  relative 
lengths  of  systole  and  diastole,  tracings  were  taken  from  rapidly  re- 
volving drums  and  compared  with  the  record  of  a  tuning  fork  which 
vibrated  at  the  rate  of  one  hundred  times  per  second.  In  this  ex- 
periment frogs  were  used,  and  adonis  applied  to  the  exposed  tissues 
immediately  surrounding  the  heart.  The  following  are  the  results 
taken  from  a  single  heart,  but  are  typical  of  each  experiment  performed. 
Measurements  taken  from  the  record  made  by  the  heart  before 
adonis  was  applied  gave  the  following  results. 
Duration  of  Systole  in  One  Hun-    Duration  of  Diastole  in  One  Hundredth 
dredth  of  a  Second.  of  a  Second. 
Readings.       70  38 
Average.         70  38 
Measurements  Taken  One  Minute  after  the  Application  of  Adonis. 
  49 
Average.         83  52 
Measurements  Taken  Five  Minutes  after  the  Application  of  Adonis. 
71  64 
75 
76 
60 
Average. 
74 
62 
