Am"ju°iyr'i9i4arm*}    Chemistry  of  Pressor  Compounds.  29$ 
Lewis,  Miller  and  Matthews  believe  the  pars  intermedia  to  be 
separated  by  the  hypophyseal  cleft  into  one  portion  closely  con- 
nected with  the  anterior  lobe  and  one  with  the  posterior.  This  may 
explain  why  a  rise  in  pressure  may  follow  the  injection  of  extracts 
of  either  lobe.  They  obtained  a  rise  in  pressure  more  frequently 
from  injections  of  extracts  of  the  anterior  lobe  than  from  those  of 
the  posterior.  Schaefer  and  Herring  were  inclined  to  the  view  that 
the  activity  of  the  anterior  lobe  might  really  be  due  to  postmortem 
infiltration. 
Lewis,  Miller  and  Matthews  found  that  after  removal  of  the 
depressor  compound,  extracts  of  the  pars  intermedia  caused  a  rise 
in  blood-pressure  without  slowing  of  the  pulse-rate.  They,  like 
Howell,  also  noted  that  extracts  of  the  posterior  lobe  caused  a  rise 
in  blood-pressure,  which  was  followed  by  a  fall,  and  that  there  was 
then  a  return  to  the  higher  level.  This  fall  after  the  primary  rise 
was  only  seen  when  extracts  of  the  posterior  lobe  were  used,  and 
they  attributed  this  to  a  second  depressor  principle  which  was  in- 
soluble in  alcohol. 
Osborne  and  Vincent 19  found  that  the  pituitaries  of  various 
teleostean  fishes  exerted  a  pressor  action,  and  claimed  that  the  cen- 
tral part  of  the  infundibular  portion  of  the  ox  pituitary  had  more 
pressor  activity  than  the  peripheral  portion.  In  a  recent  compara- 
tive study  of  the  pituitary  gland  Herring  sums  up  the  work  as 
follows :  "  The  presence  of  active  physiological  principles  in  the 
pituitary  is  associated  with  a  tissue  of  nervous  origin,1'  and  "  there 
is  reason  to  believe  that  the  granules  are  the  histological  represen- 
tatives of  the  active  principles,  and  that  they  are  the  products  of 
part  of  the  epithelial  lobe — the  cells  of  the  pars  intermedia — carried 
to,  elaborated  in,  and  stored  by,  the  pars  nervosa." 
Vincent  and  Sheen  20  took  the  position  that  pressor  principles 
could  be  found  not  only  in  the  pituitaries  and  suprarenals,  but  in 
greater  or  less  extent  in  most  tissues,  and  that  boiling  the  extracts 
19  Osborne,  W.  A.,  and  Vincent,  S.,  "Contribution  to  the  Study  of  the 
Pituitary  Body,"  Brit.  Med.  Jour.  (1900),  vol.  1,  p.  502. 
20  Vincent,  S.,  and  Sheen,  W.,  "Effects  of  Intravascular  Injections  of 
Extracts  of  Animal  Tissues,"  Jour,  of  Physiol.,  vol.  29,  p.  242  (1903).  See 
also  McCord,  C.  P.,  "  Investigation  of  the  Depressor  Action  of  Pituitary 
Extracts,  Archives  of  Int.  Med.,  vol.  8,  p.  609  (1911)  ;  Berlin,  E.,  "  Hemocholin 
und  Neosin,"  Zcits.  f.  Biol.,  vol.  57,  p.  t  (1911). 
t 
