Table 1

Effect of monoquaternary and bisquaternary ligands on oxime-induced reactivation rate constant (k r) of MEPQ-inhibited FBS AChE

Oximekr
ControlEdrophonium (50 μm)Decamethonium (200 μm)
m −1·min−1
2-PAM1-a
 Fast273  ± 79894  ± 115434  ± 34
 Slow33  ± 7118  ± 4174  ± 26
TMB4 1-b
 Fast1176  ± 776182  ± 4792281  ± 397
 Slow37  ± 7325  ± 1888  ± 15
LüH6 1-b
 Fast1114  ± 1575003  ± 4432117  ± 197
 Slow30  ± 6358  ± 3189  ± 18
HI-61-a
 Fast736  ± 80790  ± 196604  ± 142
 Slow54  ± 1066  ± 2452  ± 23

In all the cases, data were analyzed assuming a 50:50 ratio between the two kinetic species of EMP-AChE; for the determination ofk r, five or six concentrations of oxime were used ranging from 10 μm to 3 mm. Values are mean ± standard error of three or four determinations.

    • 1-a Obtained by dividing k maxby K ox. In the case of 2-PAM, the changes of k r in the presence of the two ligands were mainly contributed by the decrease of K ox with no change in k max, whereas for HI-6, no such changes was detectable in the presence of either ligand.

    • 1-b Calculated from the slope of k obs versus [oxime] plot.