Am.  Jour,  riiarm.  1 
April,  1914.  J 
Lecithin. 
175 
siders  lecithin  to  be  an  essential  component  of  food,  which  cannot 
be  constructed  from  its  elements  in  the  mammalian  body.  On  the 
other  hand,  according  to  Fingerling's  observations,  ducks  are  appar- 
ently able  to  produce  large  amounts  of  lecithin  from  inorganic  phos- 
phorus. It  must  also'  be  assumed  that  glycerophosphoric  acid  which 
has  been  absorbed  is  made  use  of  in  certain  organs  for  the  produc- 
tion of  lecithin.  The  choline  required  for  this  purpose  has  been 
shown  to  be  present  in  various  parts  of  the  organism  (Kinoshita  °) . 
Mulon,  Bernard  and  others  point  to  the  suprarenal  glands  as  the 
seat  of  formation  of  lecithin.  Moreover,  lecithin  appears  to  be 
capable  of  being  split  up  by  ferments  in  certain  organs.  Coriat, 
for  example,  believes  an  enzyme  to  be  present  in  the  brain,  which 
decomposes  lecithin  with  separation  of  choline.  He  did  not  succeed 
in  isolating  this  enzyme,  but  he  proved  that  its  action  was  destroyed 
by  heating. 
After  Bokay  had  demonstrated  that  lecithin  could  be  split  up 
by  the  secretion  from  the  small  intestine,  P.  Mayer  attempted  to 
establish  which  of  the  ferments  of  the  small  intestine  (trypsin,  erep- 
sin,  lipase)  caused  this  disintegration.  He  found  that  lecithin  was 
abundantly  split  up  by  steapsin  and  that  under  certain  conditions 
the  fatty  acids  separated  in  a  crystalline  form.  According  to  this, 
the  behaviour  of  lecithin  is  identical  with  that  found  by  Connstein  in 
the  fermentative  decomposition  of  the  true  fats.  Mayer  believes 
his  observations  to  show  that  the  enzymes  do  not  react  in  the  same 
way  upon  d-  and  1-lecithin. 
SchumofT-Simanowski  and  Sieber  also  confirm  the  action  of 
pancreatic  and  g*astric  'steapsin  in  splitting-  up  lecithin,  whereas 
their  tests,  with  lipase  of  blood  or  blood  serum  gave  a  negative  re- 
sult. It  is  not  capable  of  splitting  off  fatty  acids  from  lecithin.  It 
is  indeed  possible,  with  the  help  of  this  negative  character,  to  dis- 
tinguish lipase  from  other  lipolytic  enzymes.  Lecithin  is,  on  the 
other  hand,  decomposed  by  vegetable  ferments,  especially  by  the 
ferment  of  Ricinus  communis,  with  separation  of  fatty  acids. 
But  the  results  of  the  authors  mentioned  above  do  not  appear  to 
correspond  entirely  with  all  the  facts,  if  they  are  compared  with 
0  Choline  is  said  by  Lohmann  to  occur  in  the  suprarenal  glands,  by  von 
Fiirth  and  Schwarz  in  the  thyroid  gland  and  intestinal  extracts,  by  Schwarz 
and  Lederer  in  the  thymus,  spleen  and  lymphatic  glands,  by  Kutscher  in  flesh, 
by  Letsche  in  serum,  by  Jacobsen  in  bile,  by  Cramer  in  the  brain,  by  Bohm 
in  the  placenta,  by  Gautrelet  in  the  kidneys,  ovaries,  testicles  and  pancreas. 
