Late acute effect of S, S, S-tributyl phosphorotrithioate (DEF) in hens

Abstract

Oral administration of a single dose of S, S, S-tributyl phosphorotrithioate (DEF) caused immediate cholinergic effects in most treated hens, which were rapidly relieved by atropine sulfate treatment. Small single oral doses caused gross ataxia which regressed with time in most treated hens. Large oral doses caused a “late acute” effect 24 to 48 h after administration. The clinical sings of the “late acute” effect were identical to those produced by n-butyl mercaptan ( nBM), a hydrolytic product of DEF, and were not relieved by atropine sulfate. The administration of nBM did not result in neuropathologic lesions but resulted in slightly increased brain AChE and plasma BuChE activities. It is concluded that orally administered DEF is rapidly metabolized in the gastrointestinal tract to nBM, which causes the “late acute” effect.