HI-6 and TMB-4(Trimedoxime) were the most effective and safe of 7 cholinesterase reactivators tested as agents for the prophylaxis of proserine poisoning of male mice. The reactivator HI-6 strongly potentiated the prophylactic efficacy of a mixture of atropine and arpenal administered in the doses sufficient for the blockade of both the m- and h-cholinoreactive systems of mice. As demonstrated by experiments in vitro, HI-6 and TMB-4(Trimedoxime) did not reacivate proserine-inhibited cholinesterase. The natural anticholinesterase activity of HI-6 was negligible. Based on the correlation of the data obtained to the reported data indicating that HI-6 has a low ganglioblocking activity it is inferred that the direct effect on the receptor is of no importance for the potentiating effect. It is assumed that HI-6 modulates the cholinoreactive systems, which leads to a dramatic increase of the efficacy of cholinolytics.
        
Title: [Effect of some reactivators on cholinesterase activity in the chromodacryorrhea test in rats]. [Bulgarian] Naneva E Ref: Veterinarno Meditsinski Nauki, 13:81, 1976 : PubMed
Studied was the activity of low concentrations --- 1-10-12, and 1.10-18 -- of the specific reactivators of the enzyme cholinesterase (ChE): 2-PAM, TMB-4(Trimedoxime) Toxogonin, HS-3, and HS-6, in a chromodacryorrhea test (ChDT) with rats, daily (in the course of 30 days -- 1 ml/100 g), twice (at an interval of 10 days -- 1 ml/100 g) and once (5 mg/kg) at subcutaneous application. Described is an activating affect (observed for the first time in vivo) on ChE preduced by low and very low concentrations of reactivators of the group of oximes. HS-3 produced best activating effects. The low concentrations of the specific oxime ractivators of ChE, followed up by ChDT, can be used as sensitive quantitative indicators of the activity of ChE. They can also serve to specify the mode of action power and term of effectiveness of these reactivators.