Changes in brain acetylcholine of rats after dermal application of fenitrothion (Sumithion).

Fenitrothion (Sumithion), and organophosphorous insectide, was applied dermally to rats. Cholinesterase activity was measured in blood and brain. The concentration of the pesticide in blood plasma and acetylcholine in brain were estimated at different intervals. The maximum concentration of Fenitrothion in the plasma was found at 4 hrs while significantly elevated levels of acetylcholine were present in the brain till 24 hrs. The results suggest that the compound was readily absorbed by dermal route to produce inhibition of cholinesterase and a consequent persistent increase in brain acetylcholine.