24 
Toxic  Action  of  Uranium. 
Am.  Jour.  Pharm 
Jan.,  1891. 
poisonous.  Subcutaneous  doses  of  0-5-2-0  milligrams  per  kilo  of 
body  weight  cause  death  with  all  the  symptoms  of  acute  poisoning. 
It  is  noteworthy  that  very  small  doses  administered  subcutaneously 
are  almost  as  quickly  fatal  as  are  considerably  larger  quantities,  the 
only  difference  being  that  the  action  of  the  latter  on  the  organs 
affected  is  more  marked.  It  is  remarkable  that  during  the  first  day 
or  two  after  the  administration  of  the  poison  there  is  no  outward 
evidence  of  its  effects  save  the  pathological  character  of  the  urine, 
although  afterwards  the  toxic  action  is  increasingly  manifest,  so  that 
the  whole  nature  of  the  poisoning  may  be  said  to  be  of  a  subcuta- 
neous character. 
The  exact  symptoms  produced  by  poisonous  doses  of  uranium  are 
as  follows:  Severe  gastro-enteritis  follows  its  administration, while 
nephritis  is  induced  by  such  small  doses  as  1-2  milligrams  per  kilo 
of  body  weight.  It  is  distinguished  from  other  metallic  poisons  by 
acting  directly,  even  in  very  small  doses,  on  the  walls  of  the  blood- 
vessels. This  tendency  is  doubtless  closely  connected  with  its 
specific  action  on  the  blood  by  causing  the  haemoglobin  to  retain 
oxygen  altogether  abnormally,  in  which  respect  it  resembles  hydro- 
cyanic acid.  A  knowledge  of  this  fact  throws  considerable  light  on 
the  phenomena  attending  poisoning  by  uranium.  On  its  intro- 
duction into  the  circulation,  the  difficultly-reducible  oxyhemoglobin, 
resulting  from  its  action  above  mentioned,  probably  affects  the 
walls  of  the  blood-vessels  in  the  same  manner  as  venous  blood 
and  causes  their  dilatation.  The  failure  of  the  oxyhemoglobin 
under  the  influence  of  uranium  salts  to  part  normally  with  its  oxy- 
gen accounts  also  for  the  profound  disorganization  of  the  nutritive 
functions  which  ensues,  and  for  the  derangement  of  the  nervous 
system,  liver  and  kidneys,  which  accompanies  it.  It  also  explains  the 
general  waste  of  tissue,  resulting  in  the  emaciation  of  the  animal 
under  experiment,  which  was  a  characteristic  symptom,  and  further 
elucidates  the  first  noted  pathological  phenomenon,  viz:  the  appear- 
ance of  sugar  in  the  urine,  which  is  merely  a  sign  of  imperfect  oxi- 
dation in  the  circulatory  system,  disappearing  with  the  removal  of 
the  ultimate  cause.  Professor  Kobert  has  recommended,  on  account 
of  their  extreme  toxicity,  the  insertion  of  the  soluble  salts  of  uranium 
in  the  list  of  poisons  officially  current  in  Russia,  and  it  is  certainly 
desirable  that  other  countries  should  make  a  similar  move. 
