Conversion of O, O-diethyl-O- p-nitrophenyl thiophosphate (parathion) into an acetylcholinesterase-inhibitor by the insect fat body

Abstract

1. 1. Pure parathion (O, O-diethyl-O- p-nitrophenyl thiophosphate), which does not possess an in vitro inhibitory activity against cholinesterases, acquires this inhibitory capacity after incubation with insect tissue. 2. 2. Among the tissues of Periplaneta americana L. investigated, the fat body was the most active in this conversion of parathion. 3. 3. The capacity for this conversion of parathion (probably into O, O-diethyl O- p-nitrophenyl phosphate, paraoxon) is another property, which the fat body of the insect shares with the mammalian liver.