Blood Cholinesterase Activity Levels of Victims Intoxicated with Sarin in Matsumoto and Tokyo Subway System

Abstract

Sarin gas attack caused by AUM SHINRIKYO, Japanese cult, gave us great shock toward illegal usage of chemical warfare agent. Eighteen people died and more than fifty hundreds had received medical treatment, in Matsumoto Incident (June 27, 1994) and in Tokyo Subway Incident (March 20, 1995). We have performed toxicological tests for the blood samples drawn from 7 (Matsumoto) and 11 (Tokyo) dead and 38 (Matsumoto) injured people. Both red blood cell (RBC) acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BuChE) activities of victim’s blood samples have been measured by modified Ellman’s method using specific substrates acetylthiocholine and butyrylthiocholine, respectively. Compared to the control values of healthy donors, both RBC AChE and plasma BuChE activities were significantly (p<0.05) lowered in 7 fatalities and 16 nonfatal casualties in Matsumoto and 6 fatalities in Tokyo. The extent of the lowered activity levels was more remarkable in RBC AChE than in plasma BuChE. There were one fatal and 9 nonfatal casualties which RBC AChE activities were significantly lowered even though the counterpart plasma BuChE activities were not lowered.