
distribution and excretion of radioactivity after parenteral
administration of radioactive polydiethylstilbestrol phosphate
to rats and a cow.
polydiethylstilbestrol phosphate
(psp), a water soluble polyester of phos-
phoric acid and diethylstilbestrol, was in-
jected in rats and a cow and the distribution
and excretion of radioactivity were followed
in both species.  after a subcutaneous or
intramuscular injection the bulk of the radio-
activity was accumulated at the site of injec-
tion.  the disappearance of radioactivity from
this depot was very slow.  as late as 90 days
after the injection into rats, 20% of the
administered radioactivity was still accumu-
lated at the site of injection.  the liver was
very effective in removing labeled material
from circulating blood.  twenty-four hours
after intravenous injection in rats, about
50% of the radioactivity was recovered from
this organ.  the distribution of radioactivity
in the cow indicated that the polymer was
preferably accumulated in organs containing
reticuloendothelial cells.
