Comparison of the functional effects of dyflos, tri-o-cresyl phosphate and tri-p-ethylphenyl phosphate in chickens.

Tri-p-ethylphenyl phosphate is unique amongst the organophosphorus compounds which produce neurotoxic effects in not being an inhibitor of cholinesterase. The dysfunction it produces is also marked by some unusual features. Thus it produces a characteristic high-stepping gait which develops at varying periods after intramuscular injection but more regularly following oral administration. A careful comparison of the character, onset and development of the effects of diisopropyl phosphorofluoridate (dyflos), tri-o-cresyl phosphate and tri-p-ethylphenyl phosphate has illustrated the differences between the two former substances and tri-p-ethylphenyl phosphate. It has also confirmed a previous suggestion that this substance acts in a different manner from the other two, a suggestion supported by the histological evidence.