A Comparison of the Reactivating Efficacy of New Asymmetric Bispyridinium Oxime BI-6with Oximes HI-6 and Obidoxime on Soman-Inhibited Acetylcholinesterase in the Diaphragm and Various Parts ofthe Rat Brain

Overview

Background.
Acute poisoning with the highly toxic organophosphorus agent, soman, is not treated satisfactorilyeven by the most modern antidotes.Methods and Results. In experiments on rats, the reactivating effect of a new asymmetric bispyridinium oxime BI-6was compared with widely used oximes HI-6 and obidoxime by investigating the changes of soman-inhibited acetylcho-linesterase activity in the diaphragm and various parts of the brain in rats up to three hours following soman challenge.Our findings confirm that the new oxime BI-6 is a more effective reactivator of soman-inhibited acetylcholines-terase than obidoxime but not as effective as the oxime HI-6 expecially in the peripheral compartment.Conclusions. The new oxime BI-6 is not as effective as HI-6 which seems to have definite advantages over otheroximes in the treatment of soman poisoning.

Key words:
soman, BI-6, HI-6, obidoxime, acetylcholinesterase, diaphragm, brain, rat.