A histological and enzymatic examination was made of the neurological disruption produced in hens by two
organophosphate esters. Intraperitoneal administration of
DEF (tributyl phosphorotrithiolate) and
Merphos (tributyl phosphorotrithioite) produced central and perpheral nervous system lesions accompanied by clinical signs of
ataxia similar to those seen following administration of
tri-o-cresyl phosphate. Histological examination (utilizing the Marchi
stain) showed the occurence of spinal cord disruption before the onset of clinical
ataxia.
Oral administration of
DEF and
Merphos did not induce signs of peripheral weakness. However, severe lesions in the spinal cord and sciatic nerve were prominent. A discussion of the occurrence of central and peripheral nerve disruption either in the presence or absence of clinical
ataxia is presented. Enzymatic examination of the effect of
DEF on spinal cord and brain
esterases at various intervals following administration showed a pattern of
esterase inhibition similar to that found after
tri-o-cresyl phosphate,
dyflos and other
organophosphates. Some prolonged inhibition is believed due to the extent of initial involvement rather than to selective prolonged inhibition.