The aim of the experiments was to obtain more information on the toxicity of organophosphates and protection against them. Pretreatment of mice with CBDP increased the s.c. toxicity of soman 19.1-fold, and its i.p. toxicity 17.8-fold. The protective effect of atropine and the oximes HS-3, HS-6 and HI-6 in soman poisoning was much greater in CBDP pretreated than in control animals. Atropine + HI-6 raised the s.c. LDs0 of soman in the CBDP pretreated animals from 6.8 ~xg/kg to 166 p,g/kg (PI = 24.3), but in control animals the i.p. LD~0 was only raised from 370 ~xg/kg to 608 p.g/kg (PI = 0.6). CBDP inhibited blood and brain AChE activity, but had no effect on aliesterase (AE) activity in plasma, liver and brain of mice in vivo.
CBDP increased s.c. toxicities of sarin 11-fold, of tabun 5-fold and of VX 0.24-fold. The protective index of atropine + HS-3 in sarin poisoning, as in the case of soman poisoning, was much higher in CBDP pretreated than in control animals (20.1 : 13.6), only slightly higher in tabun poisoning (4.3:3.4) and in the case of VX poisoning lower in CBDP pretreated than in control animals (32 : 47).
The results indicate that CBDP potentiates soman, sarin and tabun toxicities mainly by blocking their binding to non-specific sites in the body.