OBJECTIVETo investigate the activity of ChE in rats poisoned by dimehypo and then treated with pralidoxime methylchloride or unithiol.

METHODRats were divided into control group (dimehypo); intervention groups [dimehypo plus pralidoxime methylchloride or dimehypo plus unithiol (sodium dimercaptopropanesulphonate)]. Rats were dosed with 4 different doses of dimehypo: 1/16, 1/8, 1/4 and 1/2 of LD50 respectively(the LD50 of dimehypo is 342 mg/kg). After being poisoned with dimehypo orally, rats were immediately injected intramuscularly with pralidoxime methylchloride or unithiol. The activity of ChE in blood was detected before and 1/2, 1, 2, 4 and 24 h after poisoning in dimehypo and intervention groups.

RESULTThe ChE activity of four dose subgroups at 1 h after poisoning were (1.04 +/- 0.21), (0.84 +/- 0.12), (0.71 +/- 0.12), (0.66 +/- 0.07) U/ml respectively; the ChE activity of pralidoxime methylchloride intervention groups were (1.01 +/- 0.18), (1.17 +/- 0.11), (1.01 +/- 0.04), (1.03 +/- 0.12) U/ml respectively; and the ChE activity of unithiol intervention groups were (1.15 +/- 0.15), (1.26 +/- 0.27), (1.08 +/- 0.08), (1.04 +/- 0.12) U/ml respectively. The inhibited ChE in blood was recovered by either treatment with pyraldoxime methylchloride or unithiol. These two drugs had similar effects of recovering the activity of ChE(P > 0.05), but at higher doses(1/4 and 1/2 of LD50) the effects of both were not so good.

CONCLUSIONPralidoxime methylchloride and unithiol could partly recover the activity of ChE inhibited by dimehypo.