Study of paraoxonase-1 function on tissue damage of dichlorvos

To examine the protective efficacy of paraoxonase-1 (PON1) against tissue damage caused by dichlorvos, purified rabbit PON1 was injected intravenously into rats 30min before they were given dichlorvos, while dichlorvos administration group and corn coil administration group were conducted to compare. Blood was collected at different time points after dichlorvos administration to examine the acetyl cholinesterase (AChE) inhibition level and clinical signs were observed after poisoning. 72h later, animals were anesthetized and the hippocampus, liver, lung and kidney were removed for observation of ultrastructure. AChE activities in PON1 pretreament group were statistically significant from dichlorvos administration group (P<0.01). The clinical signs were alleviated by PON1 significantly (P<0.05). The most common change of organophosphorus poisoning damage to liver was small lipid-like structures could be seen throughout the liver structure. In kidney, dense bodies were seen. The most significant changes in lung were lost of lamellar structure of lamellar bodies in type II alveolar epithelial cell. As for changes of hippocampus, demyaliation takes place after acute organophosphorus, but neural edema was not improved significantly in our study. In conclusion, PON1 can decrease the AChE inhibition, and alleviated clinical signs and tissue damage caused by dichlorvos.