Analysis of therapeutic effect of lipid emulsion on acute organophosphorus poisoning and acute lung injury in rats

Abstract

Objective To explore the therapeutic effect of lipid emulsion on acute organophosphorus poisoning and its consequence of acute lung injury. Methods A total of 48 sealant - grade Sprague-Dawley (SD) rats were randomly divided into four groups A,B,C,D,namely saline control group,lipid emulsion control group,the conventional therapy group and lipid emulsion administration group. After dichlorvos (DDVP) 11 mg/kg was given by intra-peritoneal injection,if there was no loss of DDVP during the injection process,the model of poisoning was considered to be made successfully.Then the rat models in four groups were respectively treated:with normal saline (5 ml/kg) intravenous injection in group A,lipid emulsion (5ml/kg) intravenous injection in group B,atropine (5 mg/kg) and pralidoxime chloride (40 mg/kg) intramuscular injection in group C,and combined use of lipid emulsion (5 ml/kg) with atropine and pralidoxime chloride in group D after administration of DDVP by intra-peritoneal injection.The activity of cholinesterase (CHE) in blood was detected before and 0.5 h,2 h and 4 h after DDVP poisoning. The clinical manifestations,the survival of rats,the wet weight of rat' s lung and the pathological changes of the lung tissue were observed within following 24 h. The rates of survival and symptoms of rats were compared between paired groups by using the x2 test,and the mean values of biomarkers were compared paired groups by using t test. Results In groups A and B,the intensity of muscular fasciculation and salivation were more severe and appeared sooner after DDVP exposure in comparison with groups C and D leading to lower survival rates in group A and B. Compared with group C,the rate of 24 h survival was higher and the intensity of muscular fasciculation was weaker in group D ( P ＜ 0.05 ).In group A and group B,the 24-hour survival rates were 1/12 and 2/12,respectively ( P ＜ 0.05 ).The levels of CHE in blood significantly decreased after DDVP poisoning ( P ＜ 0.05 ).There was no significant difference in activity of CHE between group B and group A,and in groups C and D,the levels of CHE in blood were not significantly higher than that in the group B 0.5 h after DDVP poisoning ( P ＜ O.05 ).In groups C and D,the activity of CHE in blood was significantly higher compared with group A and B,and that in group D was higher compared with C,and that in group B was higher compared with A 2 and 4 hours after DDVP poisoning ( P ＜ 0.05 ).In groups C and D,the wet weight of rat lung was significantly lighter compared with groups A and B,and that in group D was lighter compared with C,and that in group B was lighter compared with A 24 h after DDVP poisoning P ＜ 0.05 ).The electron microscopic findings showed the combined use of lipid emulsion with atropine and pralidoxime chloride obviously lessened the lung histopathologic changes after DDVP poisoning.Conclusions The lipid emulsion combined with atropine and pralidoxime chloride can be beneficial to controlling the toxic symptoms,reduce the death rate,accelerate the resume of the activity of CHE in blood,and relieve the lung injury induced by acute organophosphorus poisoning. Key words: Lipid emulsion; Acute organophosphorus poisoning; Dichlorvos (DDVP); Lung injury; Therapeutic effect