Am lngl'Sm&Tm'}   Pepsin  and  Trypsin  in  Human  Urine.  387 
OX  THE  OCCURENCE  OF  PEPSIN"  AND  TRYPSIN  IN 
NORMAL  HUMAN  URINE. 
By  Dr.  Sahli. 
The  investigation  of  the  amount  of  pepsin  in  urine  is  based  on  the 
facts  given  by  v.  Wittich  that  blood  fibrin,  both  in  neutral  and  ac'd 
solutions,  absorbs  pepsin  with  great  eagerness,  and  that  the  amount 
which  a  flake  of  fibrin  absorbs  depends  on  the  amount  of  fibrin  pre- 
sent in  the  fluid. 
To  compare  the  amount  present  in  two  perfectly  fresh  urines, 
equal  quantities  of  well-washed  fibrin  are  introduced  into 
them,  and  left  in  them  for  equal  periods.  The  urine  is  poured 
off,  and  the  flakes  washed  with  distilled  water,  after  which 
they  are  placed  in  equal  quantities  of  *1  solution  of  hydrochloric 
acid. 
Since  now,  according  to  Briicke,  within  certain  limits  the 
speed  of  digestion  is  dependent  on  the  amount  of  ferment,  con- 
versely we  may  form  an  estimate  of  the  amount  of  ferment 
present  from  the  time  required  to  effect  the  disappearance  of  the 
fibrin. 
In  this  way  Sahli  found  that  human  urine  invariably  contains  pep- 
sin, and  that  the  amount  present  undergoes  very  great  variations  in 
the  course  of  24  hours.  The  morning  urine  contains  the  greatest 
amount,  then  the  urine  before  dinner,  then  that  directly  before  sup- 
per. The  first  minimum  occurs  two  hours  after  breakfast;  the  second^ 
more  marked,  one  and  a  half  to  two  and  a  half  hours  after  the  mid- 
day maximum.  A  comparison  of  the  curve  exhibiting  these  varia- 
tions with  that  which  shows  the  secretion  of  the  fundus  of  the 
stomach,  leads  to  the  conclusion  that  the  pepsin  in  the  urine  is  de- 
rived, not  from  the  pepsinogenic  substance  of  the  gastric  glands,  but 
that  it  is  the  completed  secretion  of  the  stomach,  resorbed  along  the 
digestive  tract,  and  carried  by  the  blood  current  to  the  kidneys,  by 
which  it  is  partially  eliminated. 
Urine  also  contains  trypsin,  which,  however,  cannot  be  isolated  by 
fibrin.  Still,  Sahli  convinced  himself  that  the  amount  of  this  ferment 
also  varies,  being  regularly  diminished  after  dinner,  and  greatest  after 
breakfast.  —  Med.  Chronicle,  June  ;  Pfluger's  Arehiv,  xxxvi. 
p.  209. 
