NOTES ON THE DECOMPOSITION OF PARATHION IN LIVING OPGANISMS : Ⅳ. DISTRIBUTION OF PARATHION-SPLITTING SUBSTANCE IN VARIOUS ORGANS : COMPARISON WITH CHOLINESTERASE AND ALKALINE PHOSPHATASE

The tissue ( or organ ) distribution of parathion-splitting substance was studied in dogs and was compared with that of alkaline phoshatase and cholinesterase. The conclusions derived from this experiment are: 1. The blood serum showed the greatest parathion-splitting activity ( 257.4r PNP/g . Hour ). The liver, the lunga and the done marrow were also the important tissues which decomposed parathion. There was no significant parathionsplitting activity in the brain and the heart. 2. Blood ( plasma ) is an organ which plays the greatest role in the detoxication ( decomposition ) of parathion, and the liver is the second important. 3. There was no similarity in tissue distribution between the parathion-splitting substance and cholinesterase or alkaline phosphatese. The parathion-splitting substance is not identical either with alkaline phosphatase or cholinesterase.