OBJECTIVETo study the therapeutic efficacy and mechanism of adenosine receptor agonist N(6)-cyclopentyladenosine (CPA) against acute dichlorvos poisoning.

METHODSSoon after a certain doses of dichlorvos were given to mice and rats by gastrogavage, physiological saline, CPA, atropine or pralidoxime chloride were administered to different groups. Toxic signs and survival rate were recorded and cholinesterase (ChE) activities and acetylcholine (ACh) concentrations in whole blood were determined in treatment group with CPA and non-treatment group after dichlorvos was given to rats by gastrogavage.

RESULTS(1) The alleviated and delayed appearance of toxic signs as well as obvious prolongation of survival time was observed in CPA treatment group compared with non-treatment group. (2) ChE activities in both treatment group with CPA [(0.49 +/- 0.05) U/ml] and non-treatment group [(0.52 +/- 0.04) U/ml] were significantly lower than that [(1.56 +/- 0.15) U/ml] of the control group (P < 0.01), but there was no significant difference between treatment group and non-treatment group (P > 0.05). (3) ACh concentration [(204.24 +/- 20.48) microg/ml] in whole blood of treatment group with CPA was significantly lower than that [(230.91 +/- 25.61) microg/ml] of non-treatment group (P < 0.05).

CONCLUSIONCPA has therapeutic efficacy against acute dichlorvos poisoning, which is probably through the decrease in ACh concentration.