Detoxication of phosphonothioates and phosphonofluoridates in the rat.

0-isopropylmethyl phosphonofluoridate and 0-ethyl-S-(2-dimethylaminoethyl) methylphosphonothioate were i.m. administered in doses of 2 x LD50 to female rats and the blood acetylcholinesterase was continuously monitored using the automatic colorimeter Auto Analyzer. This activity rapidly decreased after the injection of the two organophosphates studied. If the blood flow in the leg muscles was stopped by compression and reopened by relaxation at different time intervals, acetylcholinesterase activity was either unaffected (detoxication present) or decreased (detoxication absent). It was observed that phosphonofluoridate was detoxified; on the other hand, phosphonothioate was not detoxified in the rat organism.